Bump version: v2.19.1

fix: specify full path to non-venv Python (#1881 )
Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
2024-06-13 02:38:27 -04:00 · 2024-06-13 08:18:09 +02:00 · 2024-06-12 23:16:49 -04:00 · 2024-06-12 11:32:27 -04:00 · 2024-06-12 10:46:24 -04:00 · 2024-06-11 21:24:44 +02:00
107 changed files with 3200 additions and 1344 deletions
@@ -4,7 +4,9 @@ set -o xtrace

 $PYTHON --version
 $PYTHON -m pip --version
-$PYTHON -m virtualenv -p "$PYTHON" venv
+$PYTHON -m virtualenv --version
+$PYTHON -m virtualenv --no-setuptools --no-wheel -p "$PYTHON" venv
+venv/bin/python -m pip install -U pip
 venv/bin/python -m pip install -e ".[dev]"
 venv/bin/python -m pip freeze
 venv/bin/python --version
@@ -1,32 +0,0 @@
-{
-  "problemMatcher": [
-    {
-      "severity": "warning",
-      "pattern": [
-        {
-          "regexp": "^([^:]+):(\\d+):(\\d+): ([A-DF-Z]\\d+): \\033\\[[\\d;]+m([^\\033]+).*$",
-          "file": 1,
-          "line": 2,
-          "column": 3,
-          "code": 4,
-          "message": 5
-        }
-      ],
-      "owner": "pylint-warning"
-    },
-    {
-      "severity": "error",
-      "pattern": [
-        {
-          "regexp": "^([^:]+):(\\d+):(\\d+): (E\\d+): \\033\\[[\\d;]+m([^\\033]+).*$",
-          "file": 1,
-          "line": 2,
-          "column": 3,
-          "code": 4,
-          "message": 5
-        }
-      ],
-      "owner": "pylint-error"
-    }
-  ]
-}
@@ -28,12 +28,10 @@ jobs:
    - name: Check manifest
      run: pipx run nox -s check_manifest
    - name: PyLint checks
-      run: |
-        echo "::add-matcher::$GITHUB_WORKSPACE/.github/matchers/pylint.json"
-        pipx run nox -s pylint
+      run: pipx run nox -s pylint -- --output-format=github

  test:
-    name: Test cibuildwheel on ${{ matrix.os }}
+    name: Test on ${{ matrix.os }} (${{ matrix.python_version }})
    needs: lint
    runs-on: ${{ matrix.os }}
    strategy:
@@ -51,6 +49,8 @@ jobs:
      with:
        python-version: ${{ matrix.python_version }}

+    - uses: yezz123/setup-uv@v4
+
    # Install podman on this CI instance for podman tests on linux
    # Snippet from: https://github.com/redhat-actions/podman-login/blob/main/.github/workflows/example.yml
    - name: Install latest podman
@@ -71,7 +71,7 @@ jobs:

    - name: Install dependencies
      run: |
-        python -m pip install ".[test]"
+        uv pip install --system ".[test]"

    - name: Generate a sample project
      run: |
@@ -84,6 +84,9 @@ jobs:
        output-dir: wheelhouse
      env:
        CIBW_ARCHS_MACOS: x86_64 universal2 arm64
+        CIBW_BUILD_FRONTEND: 'build[uv]'
+        CIBW_FREE_THREADED_SUPPORT: 1
+        CIBW_PRERELEASE_PYTHONS: 1

    - name: Run a sample build (GitHub Action, only)
      uses: ./
@@ -127,19 +130,41 @@ jobs:
      run: |
        python ./bin/run_tests.py --run-podman

-  test-emulated:
-    name: Test emulated cibuildwheel using qemu
+  emulated-archs:
+    name: Get qemu emulated architectures
    needs: lint
    runs-on: ubuntu-latest
-    timeout-minutes: 180
+    outputs:
+      archs: ${{ steps.archs.outputs.archs }}
    steps:
    - uses: actions/checkout@v4
    - uses: actions/setup-python@v5
      with:
        python-version: "3.x"
    - name: Install dependencies
+      run: python -m pip install ".[test]"
+    - name: Get qemu emulated architectures
+      id: archs
      run: |
-        python -m pip install ".[test]"
+        OUTPUT=$(python -c "from json import dumps; from test.utils import EMULATED_ARCHS; print(dumps(EMULATED_ARCHS))")
+        echo "${OUTPUT}"
+        echo "archs=${OUTPUT}" >> "$GITHUB_OUTPUT"
+
+  test-emulated:
+    name: Test Linux ${{ matrix.arch }} using qemu
+    needs: emulated-archs
+    runs-on: ubuntu-latest
+    timeout-minutes: 180
+    strategy:
+      matrix:
+        arch: ${{ fromJSON(needs.emulated-archs.outputs.archs) }}
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      with:
+        python-version: "3.x"
+    - name: Install dependencies
+      run: python -m pip install ".[test,uv]"

    - name: Set up QEMU
      id: qemu
@@ -148,5 +173,38 @@ jobs:
        platforms: all

    - name: Run the emulation tests
+      run: pytest --run-emulation ${{ matrix.arch }} test/test_emulation.py
+
+  test-pyodide:
+    name: Test cibuildwheel building pyodide wheels
+    needs: lint
+    runs-on: ubuntu-24.04
+    timeout-minutes: 180
+    steps:
+    - uses: actions/checkout@v4
+    - uses: actions/setup-python@v5
+      name: Install Python 3.12
+      with:
+        python-version: '3.12'
+
+    - name: Install dependencies
      run: |
-        pytest --run-emulation test/test_emulation.py
+        python -m pip install ".[test]"
+
+    - name: Generate a sample project
+      run: |
+        python -m test.test_projects test.test_0_basic.basic_project sample_proj
+
+    - name: Run a sample build (GitHub Action)
+      uses: ./
+      with:
+        package-dir: sample_proj
+        output-dir: wheelhouse
+      env:
+        CIBW_PLATFORM: pyodide
+
+    - name: Run tests with 'CIBW_PLATFORM' set to 'pyodide'
+      run: |
+        python ./bin/run_tests.py
+      env:
+        CIBW_PLATFORM: pyodide
@@ -22,9 +22,9 @@ jobs:
    steps:
    - uses: actions/checkout@v4

-    - uses: wntrblm/nox@2024.03.02
+    - uses: wntrblm/nox@2024.04.15
      with:
-        python-versions: "3.7, 3.8, 3.9, 3.10, 3.11, 3.12"
+        python-versions: "3.7, 3.8, 3.9, 3.10, 3.11, 3.12, 3.13"

    - name: "Run update: dependencies"
      run: nox --force-color -s update_constraints
@@ -1,7 +1,7 @@
 repos:

 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.5.0
+  rev: v4.6.0
  hooks:
  - id: check-case-conflict
  - id: check-merge-conflict
@@ -14,20 +14,14 @@ repos:
  - id: trailing-whitespace

 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: v0.2.2
+  rev: v0.4.8
  hooks:
  - id: ruff
    args: ["--fix", "--show-fixes"]
  - id: ruff-format

- repo: https://github.com/asottile/setup-cfg-fmt
-  rev: v2.5.0
-  hooks:
-  - id: setup-cfg-fmt
-    args: [--include-version-classifiers, --min-py-version=3.8, --max-py-version=3.12]
-
 - repo: https://github.com/pre-commit/mirrors-mypy
-  rev: v1.8.0
+  rev: v1.10.0
  hooks:
  - id: mypy
    name: mypy 3.8 on cibuildwheel/
@@ -46,6 +40,7 @@ repos:
      - types-jinja2
      - types-pyyaml
      - types-requests
+      - uv
      - validate-pyproject
  - id: mypy
    name: mypy 3.12
@@ -54,7 +49,7 @@ repos:
    additional_dependencies: *mypy-dependencies

 - repo: https://github.com/shellcheck-py/shellcheck-py
-  rev: v0.9.0.6
+  rev: v0.10.0.1
  hooks:
  - id: shellcheck

@@ -74,15 +69,15 @@ repos:
    files: ^docs/changelog.md$

 - repo: https://github.com/codespell-project/codespell
-  rev: v2.2.6
+  rev: v2.3.0
  hooks:
  - id: codespell
-    args: ["-L", "sur", "-w"]
+    args: ["-L", "sur,assertin", "-w"]
    exclude: ^docs/working-examples\.md$  # Autogenerated


 - repo: https://github.com/python-jsonschema/check-jsonschema
-  rev: 0.28.0
+  rev: 0.28.4
  hooks:
    - id: check-dependabot
    - id: check-github-actions
@@ -5,14 +5,11 @@ version: 2
 build:
  os: ubuntu-22.04
  tools:
-    python: "3.11"
-
-python:
-  install:
-    - method: pip
-      path: .
-      extra_requirements:
-        - docs
-
-mkdocs:
-  configuration: mkdocs.yml
+    python: "3.12"
+  commands:
+    - asdf plugin add uv
+    - asdf install uv latest
+    - asdf global uv latest
+    - uv venv
+    - uv pip install -e.[docs]
+    - NO_COLOR=1 .venv/bin/mkdocs build --strict --site-dir $READTHEDOCS_OUTPUT/html
@@ -1,6 +0,0 @@
-recursive-include cibuildwheel *.cfg
-recursive-include cibuildwheel *.in
-recursive-include cibuildwheel *.py
-recursive-include cibuildwheel *.toml
-recursive-include cibuildwheel *.txt
-recursive-include cibuildwheel *.typed
@@ -22,22 +22,25 @@ Python wheels are great. Building them across **Mac, Linux, Windows**, on **mult
 What does it do?
 ----------------

-|   | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | Windows Arm64 | manylinux<br/>musllinux x86_64 | manylinux<br/>musllinux i686 | manylinux<br/>musllinux aarch64 | manylinux<br/>musllinux ppc64le | manylinux<br/>musllinux s390x |
-|----------------|----|-----|-----|-----|-----|----|-----|----|-----|-----|
-| CPython 3.6    | ✅ | N/A | ✅  | ✅  | N/A | ✅  | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.7    | ✅ | N/A | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.8    | ✅ | ✅  | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.9    | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅ | ✅ | ✅  | ✅  |
-| CPython 3.10   | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.11   | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.12  | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  |
-| PyPy 3.7 v7.3  | ✅ | N/A | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A |
-| PyPy 3.8 v7.3  | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A |
-| PyPy 3.9 v7.3  | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A |
-| PyPy 3.10 v7.3 | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A |
+|                | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | Windows Arm64 | manylinux<br/>musllinux x86_64 | manylinux<br/>musllinux i686 | manylinux<br/>musllinux aarch64 | manylinux<br/>musllinux ppc64le | manylinux<br/>musllinux s390x | Pyodide |
+|----------------|----|-----|-----|-----|-----|----|-----|----|-----|-----|-----|
+| CPython 3.6    | ✅ | N/A | ✅  | ✅  | N/A | ✅  | ✅  | ✅ | ✅  | ✅  | N/A |
+| CPython 3.7    | ✅ | N/A | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  | N/A |
+| CPython 3.8    | ✅ | ✅  | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  | N/A |
+| CPython 3.9    | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅ | ✅ | ✅  | ✅  | N/A |
+| CPython 3.10   | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | N/A |
+| CPython 3.11   | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | N/A |
+| CPython 3.12   | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁴ |
+| CPython 3.13³  | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | N/A |
+| PyPy 3.7 v7.3  | ✅ | N/A | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A |
+| PyPy 3.8 v7.3  | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A |
+| PyPy 3.9 v7.3  | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A |
+| PyPy 3.10 v7.3 | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A |

 <sup>¹ PyPy is only supported for manylinux wheels.</sup><br>
 <sup>² Windows arm64 support is experimental.</sup><br>
+<sup>³ CPython 3.13 is available using the [`CIBW_PRERELEASE_PYTHONS`](https://cibuildwheel.pypa.io/en/stable/options/#prerelease-pythons) option. Free-threaded mode requires opt-in.</sup><br>
+<sup>⁴ Experimental, not yet supported on PyPI, but can be used directly in web deployment. Use `--platform pyodide` to build.</sup><br>

 - Builds manylinux, musllinux, macOS 10.9+, and Windows wheels for CPython and PyPy
 - Works on GitHub Actions, Azure Pipelines, Travis CI, AppVeyor, CircleCI, GitLab CI, and Cirrus CI
@@ -88,10 +91,10 @@ jobs:
      - uses: actions/checkout@v4

      # Used to host cibuildwheel
-      - uses: actions/setup-python@v3
+      - uses: actions/setup-python@v5

      - name: Install cibuildwheel
-        run: python -m pip install cibuildwheel==2.17.0
+        run: python -m pip install cibuildwheel==2.19.1

      - name: Build wheels
        run: python -m cibuildwheel --output-dir wheelhouse
@@ -161,21 +164,21 @@ Here are some repos that use cibuildwheel.
 | [Tornado][]                       | ![github icon][] | ![linux icon][] ![apple icon][] ![windows icon][] | Tornado is a Python web framework and asynchronous networking library. Uses stable ABI for a small C extension. |
 | [Matplotlib][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The venerable Matplotlib, a Python library with C++ portions |
 | [NCNN][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | ncnn is a high-performance neural network inference framework optimized for the mobile platform |
+| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an analytical in-process SQL database management system |
 | [Prophet][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Tool for producing high quality forecasts for time series data that has multiple seasonality with linear or non-linear growth. |
 | [MyPy][]                          | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | The compiled version of MyPy using MyPyC. |
 | [Kivy][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Open source UI framework written in Python, running on Windows, Linux, macOS, Android and iOS |
-| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an in-process SQL OLAP Database Management System |

 [scikit-learn]: https://github.com/scikit-learn/scikit-learn
-[pytorch-fairseq]: https://github.com/pytorch/fairseq
+[pytorch-fairseq]: https://github.com/facebookresearch/fairseq
 [NumPy]: https://github.com/numpy/numpy
 [Tornado]: https://github.com/tornadoweb/tornado
 [Matplotlib]: https://github.com/matplotlib/matplotlib
 [NCNN]: https://github.com/Tencent/ncnn
+[duckdb]: https://github.com/duckdb/duckdb
 [Prophet]: https://github.com/facebook/prophet
 [MyPy]: https://github.com/mypyc/mypy_mypyc-wheels
 [Kivy]: https://github.com/kivy/kivy
-[duckdb]: https://github.com/duckdb/duckdb

 [appveyor icon]: docs/data/readme_icons/appveyor.svg
 [github icon]: docs/data/readme_icons/github.svg
@@ -208,55 +211,79 @@ Changelog

 <!-- this section was generated by bin/update_readme_changelog.py -- do not edit manually -->

+### v2.19.1
+
+- 🐛 Don't require setup-python on GHA for Pyodide (#1868)
+- 🐛 Specify full python path for uv (fixes issue in 0.2.10 & 0.2.11) (#1881)
+- 🛠 Update for pip 24.1b2 on CPython 3.13. (#1879)
+- 🛠 Fix a warning in our schema generation script. (#1866)
+- 🛠 Cleaner output on pytest 8-8.2. (#1865)
+
+
+### v2.19.0
+
+See the [release post](https://iscinumpy.dev/post/cibuildwheel-2-19-0/) for more info on new features!
+
+- 🌟 Add Pyodide platform. Set with `--platform pyodide` or `CIBW_PLATFORM: pyodide` on Linux with a host Python 3.12 to build WebAssembly wheels. Not accepted on PyPI currently, but usable directly in a website using Pyodide, for live docs, etc. (#1456, #1859)
+- 🌟 Add `build[uv]` backend, which will take a pre-existing uv install (or install `cibuildwheel[uv]`) and use `uv` for all environment setup and installs on Python 3.8+. This is significantly faster in most cases. (#1856)
+- ✨ Add free-threaded macOS builds and update CPython to 3.13.0b2. (#1854)
+- 🐛 Issue copying a wheel to a non-existent output dir fixed. (#1851, #1862)
+- 🐛 Better determinism for the test environment seeding. (#1835)
+- 🛠 `VIRTUAL_ENV` variable now set. (#1842)
+- 🛠 Remove a pip<21.3 workaround. (#1842)
+- 🛠 Error handling was refactored to use exceptions. (#1719)
+- 🛠 Hardcoded paths in tests avoided. (#1834)
+- 🛠 Single Python tests made more generic. (#1835)
+- 🛠 Sped up our ci by splitting up emulation tests. (#1839)
+
+
+
+### v2.18.1
+
+- 🌟 Add free-threaded Linux and Windows builds for 3.13. New identifiers `cp313t-*`, new option `CIBW_FREE_THREADED_SUPPORT`/`tool.cibuildwheel.free-threaded-support` required to opt-in. [See the docs](https://cibuildwheel.pypa.io/en/stable/options/#free-threaded-support) for more information. (#1831)
+- ✨ The `container-engine` is now a build (non-global) option. (#1792)
+- 🛠 The build backend for cibuildwheel is now hatchling. (#1297)
+- 🛠 Significant improvements and modernization to our noxfile. (#1823)
+- 🛠 Use pylint's new GitHub Actions reporter instead of a custom matcher. (#1823)
+- 🛠 Unpin virtualenv updates for Python 3.7+ (#1830)
+- 🐛 Fix running linux tests from Windows or macOS ARM. (#1788)
+- 📚 Fix our documentation build. (#1821)
+
+
+### v2.18.0
+
+_12 May 2024_
+
+- ✨ Adds CPython 3.13 support, under the prerelease flag [CIBW_PRERELEASE_PYTHONS](https://cibuildwheel.pypa.io/en/stable/options/#prerelease-pythons). This version of cibuildwheel uses 3.13.0b1. Free-threading mode is not available yet (#1657), waiting on official binaries (planned for beta 2) and pip support.
+
+    _While CPython is in beta, the ABI can change, so your wheels might not be compatible with the final release. For this reason, we don't recommend distributing wheels until RC1, at which point 3.13 will be available in cibuildwheel without the flag._ (#1815)
+
+- ✨ Musllinux now defaults to `musllinux_1_2`. You can set the older `musllinux_1_1` via config if needed. (#1817)
+- 🛠 No longer pre-seed setuptools/wheel in virtual environments (#1819)
+- 🛠 Respect the constraints file when building with pip, matching build (#1818)
+- 🛠 Use uv to compile our pinned dependencies, 10x faster and doesn't require special setup (#1778)
+- 🐛 Fix an issue with the schema (#1788)
+- 📚 Document the new delocate error checking macOS versions (#1766)
+- 📚 Document Rust builds (#1816)
+- 📚 Speed up our readthedocs builds with uv, 26 seconds -> 6 seconds to install dependencies (#1816)
+
+
 ### v2.17.0

 _11 March 2024_

 - 🌟 Adds the ability to inherit configuration in TOML overrides. This makes certain configurations much simpler. If you're overriding an option like `before-build` or `environment`, and you just want to add an  extra command or environment variable, you can just append (or prepend) to the previous config. See [the docs](https://cibuildwheel.pypa.io/en/stable/options/#inherit) for more information. (#1730)
- 🌟 Adds official support for native arm64 macOS GitHub runners. To use them, just specify `macos-14` as an `os` of your job in your workflow file. You can also keep `macos-13` in your build matrix to build x86_64. Check out the new [GitHub Actions example config](https://cibuildwheel.pypa.io/en/stable/setup/#github-actions).
- ✨ You no longer need to specify `--platform` to run cibuildwheel locally! Instead it will your platform automatically. This was a safety feature, no longer necessary. (#1727)
+- 🌟 Adds official support for native `arm64` macOS GitHub runners. To use them, just specify `macos-14` as an `os` of your job in your workflow file. You can also keep `macos-13` in your build matrix to build `x86_64`. Check out the new [GitHub Actions example config](https://cibuildwheel.pypa.io/en/stable/setup/#github-actions).
+- ✨ You no longer need to specify `--platform` to run cibuildwheel locally! Instead it will detect your platform automatically. This was a safety feature, no longer necessary. (#1727)
 - 🛠 Removed setuptools and wheel pinned versions. This only affects old-style projects without a `pyproject.toml`, projects with `pyproject.toml` are already getting fresh versions of their `build-system.requires` installed into an isolated environment. (#1725)
 - 🛠 Improve how the GitHub Action passes arguments (#1757)
 - 🛠 Remove a system-wide install of pipx in the GitHub Action (#1745)
- 🐛 No longer will cibuildwheel override the PIP_CONSTRAINT environment variable when using the `build` frontend. Instead it will be extended. (#1675)
- 🐛 Fix a bug where building and testing both x86_86 and arm64 wheels on the same runner caused the wrong architectures in the test environment (#1750)
- 🐛 Fix a bug that prevented testing a CPython 3.8 wheel targeting macOS 11+ on x86_64 (#1768)
+- 🐛 No longer will cibuildwheel override the `PIP_CONSTRAINT` environment variable when using the `build` frontend. Instead it will be extended. (#1675)
+- 🐛 Fix a bug where building and testing both `x86_86` and `arm64` wheels on the same runner caused the wrong architectures in the test environment (#1750)
+- 🐛 Fix a bug that prevented testing a CPython 3.8 wheel targeting macOS 11+ on `x86_64` (#1768)
 - 📚 Moved the docs onto the official PyPA domain - they're now available at https://cibuildwheel.pypa.io . (#1775)
 - 📚 Docs and examples improvements (#1762, #1734)

-
-### v2.16.5
-
-_30 January 2024_
-
- 🐛 Fix an incompatibility with the GitHub Action and new GitHub Runner images for Windows that bundle Powershell 7.3+ (#1741)
- 🛠 Preliminary support for new `macos-14` arm64 runners (#1743)
-
-### v2.16.4
-
-_28 January 2024_
-
- 🛠 Update manylinux pins to upgrade from a problematic PyPy version. (#1737)
-
-### v2.16.3
-
-_26 January 2024_
-
- 🐛 Fix a bug when building from sdist, where relative paths to files in the package didn't work because the working directory was wrong (#1687)
- 🛠 Adds the ability to disable mounting the host filesystem in containers to `/host`, through the `disable_host_mount` suboption on [`CIBW_CONTAINER_ENGINE`](https://cibuildwheel.pypa.io/en/stable/options/#container-engine).
- 📚 A lot of docs improvements! (#1708, #1705, #1686, #1679, #1667, #1665)
-
-### v2.16.2
-
-_3 October 2023_
-
- 🛠 Updates CPython 3.12 version to 3.12.0, final release (#1635)
- ✨ Adds a debug option [`CIBW_DEBUG_KEEP_CONTAINER`](https://cibuildwheel.pypa.io/en/stable/options/#cibw_debug_keep_container) to stop cibuildwheel deleting build containers after the build finishes. (#1620)
- 📚 Adds support for `[tool.cibuildwheel]` checking by adding a schema compatible with the [validate-pyproject](https://github.com/abravalheri/validate-pyproject/) tool (#1622, #1628, #1629)
- 🐛 Fix parsing of `CIBW_CONTAINER_ENGINE` and `CIBW_BUILD_FRONTEND` options to not break arguments on `:` characters (#1621)
- 🐛 Fix the evaluation order of `CIBW_ENVIRONMENT` and `CIBW_ENVIRONMENT_PASS` so that `CIBW_ENVIRONMENT` assignments can reference environment variables passed through from the host machine. (#1617)
- 🛠 Supports manylinux images' deferred installation of interpreters through the `manylinux-interpreters` tool (#1630)
-
 <!-- END bin/update_readme_changelog.py -->

 ---
@@ -305,4 +332,4 @@ See also

 Another very similar tool to consider is [matthew-brett/multibuild](http://github.com/matthew-brett/multibuild). `multibuild` is a shell script toolbox for building a wheel on various platforms. It is used as a basis to build some of the big data science tools, like SciPy.

-If you are building Rust wheels, you can get by without some of the tricks required to make GLIBC work via manylinux; this is especially relevant for cross-compiling, which is easy with Rust. See [maturin-action](https://github.com/messense/maturin-action) for a tool that is optimized for building Rust wheels and cross-compiling.
+If you are building Rust wheels, you can get by without some of the tricks required to make GLIBC work via manylinux; this is especially relevant for cross-compiling, which is easy with Rust. See [maturin-action](https://github.com/PyO3/maturin-action) for a tool that is optimized for building Rust wheels and cross-compiling.
@@ -24,11 +24,11 @@ branding:
 runs:
  using: composite
  steps:
-    # Set up a non-EOL, cibuildwheel & pipx supported Python version
+    # Set up the version of Python that supports pyodide
    - uses: actions/setup-python@v5
      id: python
      with:
-        python-version: "3.8 - 3.12"
+        python-version: "3.12"
        update-environment: false

    - id: cibw
@@ -1,5 +1,9 @@
 #!/usr/bin/env python3

+# /// script
+# dependencies = ["click", "packaging", "tomli; python_version<'3.11'"]
+# ///
+

 from __future__ import annotations

@@ -13,10 +17,14 @@ from pathlib import Path
 import click
 from packaging.version import InvalidVersion, Version

-import cibuildwheel
+if sys.version_info < (3, 11):
+    import tomli as tomllib
+else:
+    import tomllib

 config = [
    # file path, version find/replace format
+    ("pyproject.toml", 'version = "{}"'),
    ("README.md", "cibuildwheel=={}"),
    ("cibuildwheel/__init__.py", '__version__ = "{}"'),
    ("docs/faq.md", "cibuildwheel=={}"),
@@ -24,7 +32,6 @@ config = [
    ("docs/setup.md", "cibuildwheel=={}"),
    ("examples/*", "cibuildwheel=={}"),
    ("examples/*", "cibuildwheel@v{}"),
-    ("setup.cfg", "version = {}"),
 ]

 RED = "\u001b[31m"
@@ -34,7 +41,8 @@ OFF = "\u001b[0m"

@click.command()
 def bump_version() -> None:
-    current_version = cibuildwheel.__version__
+    with open("pyproject.toml", "rb") as f:
+        current_version = tomllib.load(f)["project"]["version"]

    try:
        commit_date_str = subprocess.run(
@@ -181,7 +189,7 @@ def bump_version() -> None:
    print()

    print("Push the new version to GitHub with:")
-    print("    git push && git push --tags")
+    print(f"    git push && git push origin v{new_version}")
    print()

    release_url = "https://github.com/pypa/cibuildwheel/releases/new?" + urllib.parse.urlencode(
@@ -1,5 +1,9 @@
 #!/usr/bin/env python

+# /// script
+# dependencies = ["pyyaml"]
+# ///
+
 import argparse
 import copy
 import json
@@ -12,12 +16,9 @@ parser.add_argument("--schemastore", action="store_true", help="Generate schema_
 args = parser.parse_args()

 starter = """
-$id: https://github.com/pypa/cibuildwheel/blob/main/cibuildwheel/resources/cibuildwheel.schema.json
 $schema: http://json-schema.org/draft-07/schema
-additionalProperties: false
-description: cibuildwheel's settings.
-type: object
-defines:
+$id: https://github.com/pypa/cibuildwheel/blob/main/cibuildwheel/resources/cibuildwheel.schema.json
+$defs:
  inherit:
    enum:
      - none
@@ -25,6 +26,9 @@ defines:
      - append
    default: none
    description: How to inherit the parent's value.
+additionalProperties: false
+description: cibuildwheel's settings.
+type: object
 properties:
  archs:
    description: Change the architectures built on your machine by default.
@@ -44,19 +48,21 @@ properties:
    type: string_array
  build-frontend:
    default: default
-    description: Set the tool to use to build, either "pip" (default for now) or "build"
+    description: Set the tool to use to build, either "pip" (default for now), "build", or "build[uv]"
    oneOf:
-      - enum: [pip, build, default]
+      - enum: [pip, build, "build[uv]", default]
      - type: string
        pattern: '^pip; ?args:'
      - type: string
        pattern: '^build; ?args:'
+      - type: string
+        pattern: '^build\\[uv\\]; ?args:'
      - type: object
        additionalProperties: false
        required: [name]
        properties:
          name:
-            enum: [pip, build]
+            enum: [pip, build, "build[uv]"]
          args:
            type: array
            items:
@@ -100,6 +106,10 @@ properties:
    description: Set environment variables on the host to pass-through to the container
      during the build.
    type: string_array
+  free-threaded-support:
+    type: boolean
+    default: false
+    description: The project supports free-threaded builds of Python (PEP703)
  manylinux-aarch64-image:
    type: string
    description: Specify alternative manylinux / musllinux container images
@@ -223,17 +233,17 @@ items:
      type: object
      additionalProperties: false
      properties:
-        before-all: {"$ref": "#/defines/inherit"}
-        before-build: {"$ref": "#/defines/inherit"}
-        before-test: {"$ref": "#/defines/inherit"}
-        config-settings: {"$ref": "#/defines/inherit"}
-        container-engine: {"$ref": "#/defines/inherit"}
-        environment: {"$ref": "#/defines/inherit"}
-        environment-pass: {"$ref": "#/defines/inherit"}
-        repair-wheel-command: {"$ref": "#/defines/inherit"}
-        test-command: {"$ref": "#/defines/inherit"}
-        test-extras: {"$ref": "#/defines/inherit"}
-        test-requires: {"$ref": "#/defines/inherit"}
+        before-all: {"$ref": "#/$defs/inherit"}
+        before-build: {"$ref": "#/$defs/inherit"}
+        before-test: {"$ref": "#/$defs/inherit"}
+        config-settings: {"$ref": "#/$defs/inherit"}
+        container-engine: {"$ref": "#/$defs/inherit"}
+        environment: {"$ref": "#/$defs/inherit"}
+        environment-pass: {"$ref": "#/$defs/inherit"}
+        repair-wheel-command: {"$ref": "#/$defs/inherit"}
+        test-command: {"$ref": "#/$defs/inherit"}
+        test-extras: {"$ref": "#/$defs/inherit"}
+        test-requires: {"$ref": "#/$defs/inherit"}
 """
 )

@@ -243,8 +253,8 @@ for key, value in schema["properties"].items():
 non_global_options = {k: {"$ref": f"#/properties/{k}"} for k in schema["properties"]}
 del non_global_options["build"]
 del non_global_options["skip"]
-del non_global_options["container-engine"]
 del non_global_options["test-skip"]
+del non_global_options["free-threaded-support"]

 overrides["items"]["properties"]["select"]["oneOf"] = string_array
 overrides["items"]["properties"] |= non_global_options.copy()
@@ -254,6 +264,7 @@ del overrides["items"]["properties"]["archs"]
 not_linux = non_global_options.copy()

 del not_linux["environment-pass"]
+del not_linux["container-engine"]
 for key in list(not_linux):
    if "linux-" in key:
        del not_linux[key]
@@ -271,6 +282,7 @@ oses = {
    "linux": as_object(non_global_options),
    "windows": as_object(not_linux),
    "macos": as_object(not_linux),
+    "pyodide": as_object(not_linux),
 }

 oses["linux"]["properties"]["repair-wheel-command"] = {
@@ -290,8 +302,8 @@ schema["properties"] |= oses
 if args.schemastore:
    schema["$id"] = "https://json.schemastore.org/partial-cibuildwheel.json"
    schema["$schema"] = "http://json-schema.org/draft-07/schema#"
-    schema[
-        "description"
-    ] = "cibuildwheel's toml file, generated with ./bin/generate_schema.py --schemastore from cibuildwheel."
+    schema["description"] = (
+        "cibuildwheel's toml file, generated with ./bin/generate_schema.py --schemastore from cibuildwheel."
+    )

 print(json.dumps(schema, indent=2))
@@ -11,7 +11,6 @@ This will cache the results to all_known_setup.yaml; you can reprint
 the results without the `--online` setting.
 """

-
 from __future__ import annotations

 import ast
@@ -1,5 +1,13 @@
 #!/usr/bin/env python3

+# /// script
+# dependencies = [
+#   "click",
+#   "pyyaml",
+#   "pygithub",
+# ]
+# ///
+
 """
 Convert a yaml project list into a nice table.

@@ -0,0 +1,148 @@
+#!/usr/bin/env python3
+
+from __future__ import annotations
+
+import difflib
+import logging
+from dataclasses import dataclass
+from pathlib import Path
+from typing import Final
+
+import click
+import packaging.specifiers
+import requests
+import rich
+from packaging.version import InvalidVersion, Version
+from rich.logging import RichHandler
+from rich.syntax import Syntax
+
+from cibuildwheel._compat import tomllib
+
+log = logging.getLogger("cibw")
+
+# Looking up the dir instead of using utils.resources_dir
+# since we want to write to it.
+DIR: Final[Path] = Path(__file__).parent.parent.resolve()
+RESOURCES_DIR: Final[Path] = DIR / "cibuildwheel/resources"
+
+NODEJS_DIST: Final[str] = "https://nodejs.org/dist/"
+NODEJS_INDEX: Final[str] = f"{NODEJS_DIST}index.json"
+
+
+@dataclass(frozen=True, order=True)
+class VersionTuple:
+    version: Version
+    version_string: str
+
+
+def parse_nodejs_index() -> list[VersionTuple]:
+    versions: list[VersionTuple] = []
+    response = requests.get(NODEJS_INDEX)
+    response.raise_for_status()
+    versions_info = response.json()
+    for version_info in versions_info:
+        version_string = version_info.get("version", "???")
+        if not version_info.get("lts", False):
+            log.debug("Ignoring non LTS release %r", version_string)
+            continue
+        if "linux-x64" not in version_info.get("files", []):
+            log.warning(
+                "Ignoring release %r which does not include a linux-x64 binary", version_string
+            )
+            continue
+        try:
+            version = Version(version_string)
+            if version.is_devrelease:
+                log.info("Ignoring development release %r", str(version))
+                continue
+            if version.is_prerelease:
+                log.info("Ignoring pre-release %r", str(version))
+                continue
+            versions.append(VersionTuple(version, version_string))
+        except InvalidVersion:
+            log.warning("Ignoring release %r", version_string)
+    versions.sort(reverse=True)
+    return versions
+
+
+@click.command()
+@click.option("--force", is_flag=True)
+@click.option(
+    "--level", default="INFO", type=click.Choice(["WARNING", "INFO", "DEBUG"], case_sensitive=False)
+)
+def update_nodejs(force: bool, level: str) -> None:
+    logging.basicConfig(
+        level="INFO",
+        format="%(message)s",
+        datefmt="[%X]",
+        handlers=[RichHandler(rich_tracebacks=True, markup=True)],
+    )
+    log.setLevel(level)
+
+    toml_file_path = RESOURCES_DIR / "nodejs.toml"
+
+    original_toml = toml_file_path.read_text()
+    with toml_file_path.open("rb") as f:
+        nodejs_data = tomllib.load(f)
+
+    nodejs_data.pop("url")
+
+    major_versions = [VersionTuple(Version(key), key) for key in nodejs_data]
+    major_versions.sort(reverse=True)
+
+    versions = parse_nodejs_index()
+
+    # update existing versions, 1 per LTS
+    for major_version in major_versions:
+        current = Version(nodejs_data[major_version.version_string])
+        specifier = packaging.specifiers.SpecifierSet(
+            specifiers=f"=={major_version.version.major}.*"
+        )
+        for version in versions:
+            if specifier.contains(version.version) and version.version > current:
+                nodejs_data[major_version.version_string] = version.version_string
+                break
+
+    # check for a new major LTS to insert
+    if versions and versions[0].version.major > major_versions[0].version.major:
+        major_versions.insert(
+            0,
+            VersionTuple(Version(str(versions[0].version.major)), f"v{versions[0].version.major}"),
+        )
+        nodejs_data[major_versions[0].version_string] = versions[0].version_string
+
+    versions_toml = "\n".join(
+        f'{major_version.version_string} = "{nodejs_data[major_version.version_string]}"'
+        for major_version in major_versions
+    )
+    result_toml = f'url = "{NODEJS_DIST}"\n{versions_toml}\n'
+
+    rich.print()  # spacer
+
+    if original_toml == result_toml:
+        rich.print("[green]Check complete, nodejs version unchanged.")
+        return
+
+    rich.print("nodejs version updated.")
+    rich.print("Changes:")
+    rich.print()
+
+    toml_relpath = toml_file_path.relative_to(DIR).as_posix()
+    diff_lines = difflib.unified_diff(
+        original_toml.splitlines(keepends=True),
+        result_toml.splitlines(keepends=True),
+        fromfile=toml_relpath,
+        tofile=toml_relpath,
+    )
+    rich.print(Syntax("".join(diff_lines), "diff", theme="ansi_light"))
+    rich.print()
+
+    if force:
+        toml_file_path.write_text(result_toml)
+        rich.print("[green]TOML file updated.")
+    else:
+        rich.print("[yellow]File left unchanged. Use --force flag to update.")
+
+
+if __name__ == "__main__":
+    update_nodejs()
@@ -58,7 +58,7 @@ AnyConfig = Union[ConfigWinCP, ConfigWinPP, ConfigMacOS]


 class WindowsVersions:
-    def __init__(self, arch_str: ArchStr) -> None:
+    def __init__(self, arch_str: ArchStr, free_threaded: bool) -> None:
        response = requests.get("https://api.nuget.org/v3/index.json")
        response.raise_for_status()
        api_info = response.json()
@@ -72,7 +72,11 @@ class WindowsVersions:

        self.arch_str = arch_str
        self.arch = ARCH_DICT[arch_str]
+        self.free_threaded = free_threaded
+
        package = PACKAGE_DICT[arch_str]
+        if free_threaded:
+            package = f"{package}-freethreaded"

        response = requests.get(f"{endpoint}{package}/index.json")
        response.raise_for_status()
@@ -92,8 +96,9 @@ class WindowsVersions:
        if not versions:
            return None

+        flags = "t" if self.free_threaded else ""
        version = versions[0]
-        identifier = f"cp{version.major}{version.minor}-{self.arch}"
+        identifier = f"cp{version.major}{version.minor}{flags}-{self.arch}"
        return ConfigWinCP(
            identifier=identifier,
            version=self.version_dict[version],
@@ -233,9 +238,12 @@ class CPythonVersions:

 class AllVersions:
    def __init__(self) -> None:
-        self.windows_32 = WindowsVersions("32")
-        self.windows_64 = WindowsVersions("64")
-        self.windows_arm64 = WindowsVersions("ARM64")
+        self.windows_32 = WindowsVersions("32", False)
+        self.windows_t_32 = WindowsVersions("32", True)
+        self.windows_64 = WindowsVersions("64", False)
+        self.windows_t_64 = WindowsVersions("64", True)
+        self.windows_arm64 = WindowsVersions("ARM64", False)
+        self.windows_t_arm64 = WindowsVersions("ARM64", True)
        self.windows_pypy_64 = PyPyVersions("64")

        self.macos_cpython = CPythonVersions()
@@ -259,14 +267,19 @@ class AllVersions:
                    config_update = self.macos_pypy.update_version_macos(spec)
                elif "macosx_arm64" in identifier:
                    config_update = self.macos_pypy_arm64.update_version_macos(spec)
-        elif "win32" in identifier:
-            if identifier.startswith("cp"):
-                config_update = self.windows_32.update_version_windows(spec)
+        elif "t-win32" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_32.update_version_windows(spec)
+        elif "win32" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_32.update_version_windows(spec)
+        elif "t-win_amd64" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_64.update_version_windows(spec)
        elif "win_amd64" in identifier:
            if identifier.startswith("cp"):
                config_update = self.windows_64.update_version_windows(spec)
            elif identifier.startswith("pp"):
                config_update = self.windows_pypy_64.update_version_windows(spec)
+        elif "t-win_arm64" in identifier and identifier.startswith("cp"):
+            config_update = self.windows_t_arm64.update_version_windows(spec)
        elif "win_arm64" in identifier and identifier.startswith("cp"):
            config_update = self.windows_arm64.update_version_windows(spec)

@@ -25,9 +25,9 @@ DIR: Final[Path] = Path(__file__).parent.parent.resolve()
 RESOURCES_DIR: Final[Path] = DIR / "cibuildwheel/resources"

 GET_VIRTUALENV_GITHUB: Final[str] = "https://github.com/pypa/get-virtualenv"
-GET_VIRTUALENV_URL_TEMPLATE: Final[
-    str
-] = f"{GET_VIRTUALENV_GITHUB}/blob/{{version}}/public/virtualenv.pyz?raw=true"
+GET_VIRTUALENV_URL_TEMPLATE: Final[str] = (
+    f"{GET_VIRTUALENV_GITHUB}/blob/{{version}}/public/virtualenv.pyz?raw=true"
+)


@dataclass(frozen=True, order=True)
@@ -53,10 +53,6 @@ def git_ls_remote_versions(url) -> list[VersionTuple]:
            if version.is_prerelease:
                log.info("Ignoring pre-release %r", str(version))
                continue
-            # Do not upgrade past 20.22.0 to keep python 3.6 compat
-            if version >= Version("20.22.0"):
-                log.info("Ignoring %r which is not compatible with python 3.6", str(version))
-                continue
            versions.append(VersionTuple(version, version_string))
        except InvalidVersion:
            log.warning("Ignoring ref %r", ref)
@@ -82,15 +78,20 @@ def update_virtualenv(force: bool, level: str) -> None:

    original_toml = toml_file_path.read_text()
    with toml_file_path.open("rb") as f:
-        loaded_file = tomllib.load(f)
-    version = str(loaded_file["version"])
+        configurations = tomllib.load(f)
+    default = configurations.pop("default")
+    version = str(default["version"])
    versions = git_ls_remote_versions(GET_VIRTUALENV_GITHUB)
    if versions[0].version > Version(version):
        version = versions[0].version_string

-    result_toml = (
-        f'version = "{version}"\n'
-        f'url = "{GET_VIRTUALENV_URL_TEMPLATE.format(version=version)}"\n'
+    configurations["default"] = {
+        "version": version,
+        "url": GET_VIRTUALENV_URL_TEMPLATE.format(version=version),
+    }
+    result_toml = "".join(
+        f'{key} = {{ version = "{value["version"]}", url = "{value["url"]}" }}\n'
+        for key, value in configurations.items()
    )

    rich.print()  # spacer
@@ -1,3 +1,3 @@
 from __future__ import annotations

-__version__ = "2.17.0"
+__version__ = "2.19.1"
@@ -1,11 +1,13 @@
 from __future__ import annotations

 import argparse
+import dataclasses
 import os
 import shutil
 import sys
 import tarfile
 import textwrap
+import traceback
 import typing
 from collections.abc import Iterable, Sequence, Set
 from pathlib import Path
@@ -15,8 +17,10 @@ from typing import Protocol
 import cibuildwheel
 import cibuildwheel.linux
 import cibuildwheel.macos
+import cibuildwheel.pyodide
 import cibuildwheel.util
 import cibuildwheel.windows
+from cibuildwheel import errors
 from cibuildwheel._compat.typing import assert_never
 from cibuildwheel.architecture import Architecture, allowed_architectures_check
 from cibuildwheel.logger import log
@@ -30,10 +34,38 @@ from cibuildwheel.util import (
    chdir,
    detect_ci_provider,
    fix_ansi_codes_for_github_actions,
+    strtobool,
 )


+@dataclasses.dataclass
+class GlobalOptions:
+    print_traceback_on_error: bool = True  # decides what happens when errors are hit.
+
+
 def main() -> None:
+    global_options = GlobalOptions()
+    try:
+        main_inner(global_options)
+    except errors.FatalError as e:
+        message = e.args[0]
+        if log.step_active:
+            log.step_end_with_error(message)
+        else:
+            print(f"cibuildwheel: {message}", file=sys.stderr)
+
+        if global_options.print_traceback_on_error:
+            traceback.print_exc(file=sys.stderr)
+
+        sys.exit(e.return_code)
+
+
+def main_inner(global_options: GlobalOptions) -> None:
+    """
+    `main_inner` is the same as `main`, but it raises FatalError exceptions
+    rather than exiting directly.
+    """
+
    parser = argparse.ArgumentParser(
        description="Build wheels for all the platforms.",
        epilog="""
@@ -45,7 +77,7 @@ def main() -> None:

    parser.add_argument(
        "--platform",
-        choices=["auto", "linux", "macos", "windows"],
+        choices=["auto", "linux", "macos", "windows", "pyodide"],
        default=None,
        help="""
            Platform to build for. Use this option to override the
@@ -131,8 +163,17 @@ def main() -> None:
        help="Enable pre-release Python versions if available.",
    )

+    parser.add_argument(
+        "--debug-traceback",
+        action="store_true",
+        default=strtobool(os.environ.get("CIBW_DEBUG_TRACEBACK", "0")),
+        help="Print a full traceback for all errors",
+    )
+
    args = CommandLineArguments(**vars(parser.parse_args()))

+    global_options.print_traceback_on_error = args.debug_traceback
+
    args.package_dir = args.package_dir.resolve()

    # This are always relative to the base directory, even in SDist builds
@@ -176,11 +217,10 @@ def _compute_platform_only(only: str) -> PlatformName:
        return "macos"
    if "win_" in only or "win32" in only:
        return "windows"
-    print(
-        f"Invalid --only='{only}', must be a build selector with a known platform",
-        file=sys.stderr,
-    )
-    sys.exit(2)
+    if "pyodide_" in only:
+        return "pyodide"
+    msg = f"Invalid --only='{only}', must be a build selector with a known platform"
+    raise errors.ConfigurationError(msg)


 def _compute_platform_auto() -> PlatformName:
@@ -191,34 +231,27 @@ def _compute_platform_auto() -> PlatformName:
    elif sys.platform == "win32":
        return "windows"
    else:
-        print(
+        msg = (
            'cibuildwheel: Unable to detect platform from "sys.platform". cibuildwheel doesn\'t '
            "support building wheels for this platform. You might be able to build for a different "
-            "platform using the --platform argument. Check --help output for more information.",
-            file=sys.stderr,
+            "platform using the --platform argument. Check --help output for more information."
        )
-        sys.exit(2)
+        raise errors.ConfigurationError(msg)


 def _compute_platform(args: CommandLineArguments) -> PlatformName:
    platform_option_value = args.platform or os.environ.get("CIBW_PLATFORM", "auto")

    if args.only and args.platform is not None:
-        print(
-            "--platform cannot be specified with --only, it is computed from --only",
-            file=sys.stderr,
-        )
-        sys.exit(2)
+        msg = "--platform cannot be specified with --only, it is computed from --only"
+        raise errors.ConfigurationError(msg)
    if args.only and args.archs is not None:
-        print(
-            "--arch cannot be specified with --only, it is computed from --only",
-            file=sys.stderr,
-        )
-        sys.exit(2)
+        msg = "--arch cannot be specified with --only, it is computed from --only"
+        raise errors.ConfigurationError(msg)

    if platform_option_value not in PLATFORMS | {"auto"}:
-        print(f"cibuildwheel: Unsupported platform: {platform_option_value}", file=sys.stderr)
-        sys.exit(2)
+        msg = f"Unsupported platform: {platform_option_value}"
+        raise errors.ConfigurationError(msg)

    if args.only:
        return _compute_platform_only(args.only)
@@ -233,11 +266,9 @@ class PlatformModule(Protocol):
    # is applied to a module
    def get_python_configurations(
        self, build_selector: BuildSelector, architectures: Set[Architecture]
-    ) -> Sequence[GenericPythonConfiguration]:
-        ...
+    ) -> Sequence[GenericPythonConfiguration]: ...

-    def build(self, options: Options, tmp_path: Path) -> None:
-        ...
+    def build(self, options: Options, tmp_path: Path) -> None: ...


 # pylint: disable-next=inconsistent-return-statements
@@ -248,11 +279,18 @@ def get_platform_module(platform: PlatformName) -> PlatformModule:
        return cibuildwheel.windows
    if platform == "macos":
        return cibuildwheel.macos
+    if platform == "pyodide":
+        return cibuildwheel.pyodide
    assert_never(platform)


 def build_in_directory(args: CommandLineArguments) -> None:
    platform: PlatformName = _compute_platform(args)
+    if platform == "pyodide" and sys.platform == "win32":
+        msg = "cibuildwheel: Building for pyodide is not supported on Windows"
+        print(msg, file=sys.stderr)
+        sys.exit(2)
+
    options = compute_options(platform=platform, command_line_arguments=args, env=os.environ)

    package_dir = options.globals.package_dir
@@ -260,9 +298,8 @@ def build_in_directory(args: CommandLineArguments) -> None:

    if not any(package_dir.joinpath(name).exists() for name in package_files):
        names = ", ".join(sorted(package_files, reverse=True))
-        msg = f"cibuildwheel: Could not find any of {{{names}}} at root of package"
-        print(msg, file=sys.stderr)
-        sys.exit(2)
+        msg = f"Could not find any of {{{names}}} at root of package"
+        raise errors.ConfigurationError(msg)

    platform_module = get_platform_module(platform)
    identifiers = get_build_identifiers(
@@ -293,16 +330,14 @@ def build_in_directory(args: CommandLineArguments) -> None:
        options.check_for_invalid_configuration(identifiers)
        allowed_architectures_check(platform, options.globals.architectures)
    except ValueError as err:
-        print("cibuildwheel:", *err.args, file=sys.stderr)
-        sys.exit(4)
+        raise errors.DeprecationError(*err.args) from err

    if not identifiers:
-        print(
-            f"cibuildwheel: No build identifiers selected: {options.globals.build_selector}",
-            file=sys.stderr,
-        )
-        if not args.allow_empty:
-            sys.exit(3)
+        message = f"No build identifiers selected: {options.globals.build_selector}"
+        if args.allow_empty:
+            print(f"cibuildwheel: {message}", file=sys.stderr)
+        else:
+            raise errors.NothingToDoError(message)

    output_dir = options.globals.output_dir

@@ -357,7 +392,9 @@ def print_preamble(platform: str, options: Options, identifiers: Sequence[str])


 def get_build_identifiers(
-    platform_module: PlatformModule, build_selector: BuildSelector, architectures: Set[Architecture]
+    platform_module: PlatformModule,
+    build_selector: BuildSelector,
+    architectures: Set[Architecture],
 ) -> list[str]:
    python_configurations = platform_module.get_python_configurations(build_selector, architectures)
    return [config.identifier for config in python_configurations]
@@ -15,6 +15,7 @@ PRETTY_NAMES: Final[dict[PlatformName, str]] = {
    "linux": "Linux",
    "macos": "macOS",
    "windows": "Windows",
+    "pyodide": "Pyodide",
 }

 ARCH_SYNONYMS: Final[list[dict[PlatformName, str | None]]] = [
@@ -46,6 +47,9 @@ class Architecture(Enum):
    AMD64 = "AMD64"
    ARM64 = "ARM64"

+    # WebAssembly
+    wasm32 = "wasm32"
+
    # Allow this to be sorted
    def __lt__(self, other: Architecture) -> bool:
        return self.value < other.value
@@ -72,8 +76,9 @@ class Architecture(Enum):
        return result

    @staticmethod
-    def auto_archs(platform: PlatformName) -> set[Architecture]:
-        native_machine = platform_module.machine()
+    def native_arch(platform: PlatformName) -> Architecture | None:
+        if platform == "pyodide":
+            return Architecture.wasm32

        # Cross-platform support. Used for --print-build-identifiers or docker builds.
        host_platform: PlatformName = (
@@ -82,6 +87,7 @@ class Architecture(Enum):
            else ("macos" if sys.platform.startswith("darwin") else "linux")
        )

+        native_machine = platform_module.machine()
        native_architecture = Architecture(native_machine)

        # we might need to rename the native arch to the machine we're running
@@ -93,11 +99,18 @@ class Architecture(Enum):

                    if synonym is None:
                        # can't build anything on this platform
-                        return set()
+                        return None

                    native_architecture = Architecture(synonym)

-        result = {native_architecture}
+        return native_architecture
+
+    @staticmethod
+    def auto_archs(platform: PlatformName) -> set[Architecture]:
+        native_arch = Architecture.native_arch(platform)
+        if native_arch is None:
+            return set()  # can't build anything on this platform
+        result = {native_arch}

        if platform == "linux" and Architecture.x86_64 in result:
            # x86_64 machines can run i686 containers
@@ -120,6 +133,7 @@ class Architecture(Enum):
            },
            "macos": {Architecture.x86_64, Architecture.arm64, Architecture.universal2},
            "windows": {Architecture.x86, Architecture.AMD64, Architecture.ARM64},
+            "pyodide": {Architecture.wasm32},
        }
        return all_archs_map[platform]

@@ -0,0 +1,27 @@
+"""
+Errors that can cause the build to fail. Each subclass of FatalError has
+a different return code, by defining them all here, we can ensure that they're
+semantically clear and unique.
+"""
+
+
+class FatalError(BaseException):
+    """
+    Raising an error of this type will cause the message to be printed to
+    stderr and the process to be terminated. Within cibuildwheel, raising this
+    exception produces a better error message, and optional traceback.
+    """
+
+    return_code: int = 1
+
+
+class ConfigurationError(FatalError):
+    return_code = 2
+
+
+class NothingToDoError(FatalError):
+    return_code = 3
+
+
+class DeprecationError(FatalError):
+    return_code = 4
@@ -12,8 +12,7 @@ __all__ = ("Printable", "dump_python_configurations")


 class Printable(Protocol):
-    def __str__(self) -> str:
-        ...
+    def __str__(self) -> str: ...


 def dump_python_configurations(
@@ -8,11 +8,14 @@ from dataclasses import dataclass
 from pathlib import Path, PurePath, PurePosixPath
 from typing import OrderedDict, Tuple

+from packaging.version import Version
+
+from . import errors
 from ._compat.typing import assert_never
 from .architecture import Architecture
 from .logger import log
-from .oci_container import OCIContainer
-from .options import Options
+from .oci_container import OCIContainer, OCIContainerEngineConfig
+from .options import BuildOptions, Options
 from .typing import PathOrStr
 from .util import (
    AlreadyBuiltWheelError,
@@ -44,6 +47,7 @@ class PythonConfiguration:
 class BuildStep:
    platform_configs: list[PythonConfiguration]
    platform_tag: str
+    container_engine: OCIContainerEngineConfig
    container_image: str


@@ -65,8 +69,9 @@ def get_python_configurations(
    ]


-def container_image_for_python_configuration(config: PythonConfiguration, options: Options) -> str:
-    build_options = options.build_options(config.identifier)
+def container_image_for_python_configuration(
+    config: PythonConfiguration, build_options: BuildOptions
+) -> str:
    # e.g
    # identifier is 'cp310-manylinux_x86_64'
    # platform_tag is 'manylinux_x86_64'
@@ -91,15 +96,18 @@ def get_build_steps(
    Groups PythonConfigurations into BuildSteps. Each BuildStep represents a
    separate container instance.
    """
-    steps = OrderedDict[Tuple[str, str, str], BuildStep]()
+    steps = OrderedDict[Tuple[str, str, str, OCIContainerEngineConfig], BuildStep]()

    for config in python_configurations:
        _, platform_tag = config.identifier.split("-", 1)

-        before_all = options.build_options(config.identifier).before_all
-        container_image = container_image_for_python_configuration(config, options)
+        build_options = options.build_options(config.identifier)

-        step_key = (platform_tag, container_image, before_all)
+        before_all = build_options.before_all
+        container_image = container_image_for_python_configuration(config, build_options)
+        container_engine = build_options.container_engine
+
+        step_key = (platform_tag, container_image, before_all, container_engine)

        if step_key in steps:
            steps[step_key].platform_configs.append(config)
@@ -107,6 +115,7 @@ def get_build_steps(
            steps[step_key] = BuildStep(
                platform_configs=[config],
                platform_tag=platform_tag,
+                container_engine=container_engine,
                container_image=container_image,
            )

@@ -139,11 +148,7 @@ def check_all_python_exist(
            exist = False
    if not exist:
        message = "\n".join(messages)
-        print(
-            f"cibuildwheel:\n{message}",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+        raise errors.FatalError(message)


 def build_in_container(
@@ -188,6 +193,8 @@ def build_in_container(
        log.build_start(config.identifier)
        build_options = options.build_options(config.identifier)
        build_frontend = build_options.build_frontend or BuildFrontendConfig("pip")
+        use_uv = build_frontend.name == "build[uv]" and Version(config.version) >= Version("3.8")
+        pip = ["uv", "pip"] if use_uv else ["pip"]

        dependency_constraint_flags: list[PathOrStr] = []

@@ -215,19 +222,19 @@ def build_in_container(
        # check config python is still on PATH
        which_python = container.call(["which", "python"], env=env, capture_output=True).strip()
        if PurePosixPath(which_python) != python_bin / "python":
-            print(
-                "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.",
-                file=sys.stderr,
-            )
-            sys.exit(1)
+            msg = "python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it."
+            raise errors.FatalError(msg)

-        which_pip = container.call(["which", "pip"], env=env, capture_output=True).strip()
-        if PurePosixPath(which_pip) != python_bin / "pip":
-            print(
-                "cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.",
-                file=sys.stderr,
-            )
-            sys.exit(1)
+        if use_uv:
+            which_uv = container.call(["which", "uv"], env=env, capture_output=True).strip()
+            if not which_uv:
+                msg = "uv not found on PATH. You must use a supported manylinux or musllinux environment with uv."
+                raise errors.FatalError(msg)
+        else:
+            which_pip = container.call(["which", "pip"], env=env, capture_output=True).strip()
+            if PurePosixPath(which_pip) != python_bin / "pip":
+                msg = "pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it."
+                raise errors.FatalError(msg)

        compatible_wheel = find_compatible_wheel(built_wheels, config.identifier)
        if compatible_wheel:
@@ -271,10 +278,12 @@ def build_in_container(
                    ],
                    env=env,
                )
-            elif build_frontend.name == "build":
+            elif build_frontend.name == "build" or build_frontend.name == "build[uv]":
                if not 0 <= build_options.build_verbosity < 2:
                    msg = f"build_verbosity {build_options.build_verbosity} is not supported for build frontend. Ignoring."
                    log.warning(msg)
+                if use_uv:
+                    extra_flags += ["--installer=uv"]
                container.call(
                    [
                        "python",
@@ -319,17 +328,33 @@ def build_in_container(

            # set up a virtual environment to install and test from, to make sure
            # there are no dependencies that were pulled in at build time.
-            container.call(["pip", "install", "virtualenv", *dependency_constraint_flags], env=env)
+            if not use_uv:
+                container.call(
+                    ["pip", "install", "virtualenv", *dependency_constraint_flags], env=env
+                )

            testing_temp_dir = PurePosixPath(
                container.call(["mktemp", "-d"], capture_output=True).strip()
            )
            venv_dir = testing_temp_dir / "venv"

-            container.call(["python", "-m", "virtualenv", "--no-download", venv_dir], env=env)
+            if use_uv:
+                container.call(["uv", "venv", venv_dir], env=env)
+            else:
+                # Use embedded dependencies from virtualenv to ensure determinism
+                venv_args = ["--no-periodic-update", "--pip=embed"]
+                # In Python<3.12, setuptools & wheel are installed as well
+                if Version(config.version) < Version("3.12"):
+                    venv_args.extend(("--setuptools=embed", "--wheel=embed"))
+                container.call(["python", "-m", "virtualenv", *venv_args, venv_dir], env=env)

            virtualenv_env = env.copy()
            virtualenv_env["PATH"] = f"{venv_dir / 'bin'}:{virtualenv_env['PATH']}"
+            virtualenv_env["VIRTUAL_ENV"] = str(venv_dir)
+
+            # TODO remove me once virtualenv provides pip>=24.1b1
+            if config.version == "3.13" and not use_uv:
+                container.call(["pip", "install", "pip>=24.1b1"], env=virtualenv_env)

            if build_options.before_test:
                before_test_prepared = prepare_command(
@@ -347,13 +372,13 @@ def build_in_container(
            # Let's just pick the first one.
            wheel_to_test = repaired_wheels[0]
            container.call(
-                ["pip", "install", str(wheel_to_test) + build_options.test_extras],
+                [*pip, "install", str(wheel_to_test) + build_options.test_extras],
                env=virtualenv_env,
            )

            # Install any requirements to run the tests
            if build_options.test_requires:
-                container.call(["pip", "install", *build_options.test_requires], env=virtualenv_env)
+                container.call([*pip, "install", *build_options.test_requires], env=virtualenv_env)

            # Run the tests from a different directory
            test_command_prepared = prepare_command(
@@ -388,29 +413,6 @@ def build_in_container(


 def build(options: Options, tmp_path: Path) -> None:  # noqa: ARG001
-    try:
-        # check the container engine is installed
-        subprocess.run(
-            [options.globals.container_engine.name, "--version"],
-            check=True,
-            stdout=subprocess.DEVNULL,
-        )
-    except subprocess.CalledProcessError:
-        print(
-            unwrap(
-                f"""
-                cibuildwheel: {options.globals.container_engine} not found. An
-                OCI exe like Docker or Podman is required to run Linux builds.
-                If you're building on Travis CI, add `services: [docker]` to
-                your .travis.yml. If you're building on Circle CI in Linux,
-                add a `setup_remote_docker` step to your .circleci/config.yml.
-                If you're building on Cirrus CI, use `docker_builder` task.
-                """
-            ),
-            file=sys.stderr,
-        )
-        sys.exit(2)
-
    python_configurations = get_python_configurations(
        options.globals.build_selector, options.globals.architectures
    )
@@ -425,6 +427,26 @@ def build(options: Options, tmp_path: Path) -> None:  # noqa: ARG001
    container_package_dir = container_project_path / abs_package_dir.relative_to(cwd)

    for build_step in get_build_steps(options, python_configurations):
+        try:
+            # check the container engine is installed
+            subprocess.run(
+                [build_step.container_engine.name, "--version"],
+                check=True,
+                stdout=subprocess.DEVNULL,
+            )
+        except subprocess.CalledProcessError as error:
+            msg = unwrap(
+                f"""
+                cibuildwheel: {build_step.container_engine.name} not found. An
+                OCI exe like Docker or Podman is required to run Linux builds.
+                If you're building on Travis CI, add `services: [docker]` to
+                your .travis.yml. If you're building on Circle CI in Linux,
+                add a `setup_remote_docker` step to your .circleci/config.yml.
+                If you're building on Cirrus CI, use `docker_builder` task.
+                """
+            )
+            raise errors.ConfigurationError(msg) from error
+
        try:
            ids_to_build = [x.identifier for x in build_step.platform_configs]
            log.step(f"Starting container image {build_step.container_image}...")
@@ -435,7 +457,7 @@ def build(options: Options, tmp_path: Path) -> None:  # noqa: ARG001
                image=build_step.container_image,
                enforce_32_bit=build_step.platform_tag.endswith("i686"),
                cwd=container_project_path,
-                engine=options.globals.container_engine,
+                engine=build_step.container_engine,
            ) as container:
                build_in_container(
                    options=options,
@@ -446,11 +468,9 @@ def build(options: Options, tmp_path: Path) -> None:  # noqa: ARG001
                )

        except subprocess.CalledProcessError as error:
-            log.step_end_with_error(
-                f"Command {error.cmd} failed with code {error.returncode}. {error.stdout}"
-            )
            troubleshoot(options, error)
-            sys.exit(1)
+            msg = f"Command {error.cmd} failed with code {error.returncode}. {error.stdout or ''}"
+            raise errors.FatalError(msg) from error


 def _matches_prepared_command(error_cmd: Sequence[str], command_template: str) -> bool:
@@ -469,7 +489,6 @@ def troubleshoot(options: Options, error: Exception) -> None:
        )  # TODO allow matching of overrides too?
    ):
        # the wheel build step or the repair step failed
-        print("Checking for common errors...")
        so_files = list(options.globals.package_dir.glob("**/*.so"))

        if so_files:
@@ -34,6 +34,7 @@ PLATFORM_IDENTIFIER_DESCRIPTIONS: Final[dict[str, str]] = {
    "macosx_x86_64": "macOS x86_64",
    "macosx_universal2": "macOS Universal 2 - x86_64 and arm64",
    "macosx_arm64": "macOS arm64 - Apple Silicon",
+    "pyodide_wasm32": "Pyodide",
 }


@@ -151,6 +152,10 @@ class Logger:
            c = self.colors
            print(f"{c.bright_red}Error{c.end}: {error}\n", file=sys.stderr)

+    @property
+    def step_active(self) -> bool:
+        return self.step_start_time is not None
+
    def _start_fold_group(self, name: str) -> None:
        self._end_fold_group()
        self.active_fold_group_name = name
@@ -1,6 +1,5 @@
 from __future__ import annotations

-import contextlib
 import functools
 import os
 import platform
@@ -15,7 +14,9 @@ from pathlib import Path
 from typing import Literal, Tuple

 from filelock import FileLock
+from packaging.version import Version

+from . import errors
 from ._compat.typing import assert_never
 from .architecture import Architecture
 from .environment import ParsedEnvironment
@@ -30,12 +31,16 @@ from .util import (
    BuildSelector,
    NonPlatformWheelError,
    call,
+    combine_constraints,
    detect_ci_provider,
    download,
    find_compatible_wheel,
+    find_uv,
+    free_thread_enable_313,
    get_build_verbosity_extra_flags,
    get_pip_version,
    install_certifi_script,
+    move_file,
    prepare_command,
    read_python_configs,
    shell,
@@ -46,6 +51,7 @@ from .util import (
 )


+@functools.lru_cache(maxsize=None)
 def get_macos_version() -> tuple[int, int]:
    """
    Returns the macOS major/minor version, as a tuple, e.g. (10, 15) or (11, 0)
@@ -57,9 +63,29 @@ def get_macos_version() -> tuple[int, int]:
    """
    version_str, _, _ = platform.mac_ver()
    version = tuple(map(int, version_str.split(".")[:2]))
+    if (10, 15) < version < (11, 0):
+        # When built against an older macOS SDK, Python will report macOS 10.16
+        # instead of the real version.
+        version_str = call(
+            sys.executable,
+            "-sS",
+            "-c",
+            "import platform; print(platform.mac_ver()[0])",
+            env={"SYSTEM_VERSION_COMPAT": "0"},
+            capture_stdout=True,
+        )
+        version = tuple(map(int, version_str.split(".")[:2]))
    return typing.cast(Tuple[int, int], version)


+@functools.lru_cache(maxsize=None)
+def get_test_macosx_deployment_target() -> str:
+    version = get_macos_version()
+    if version >= (11, 0):
+        return f"{version[0]}.0"
+    return f"{version[0]}.{version[1]}"
+
+
 def get_macos_sdks() -> list[str]:
    output = call("xcodebuild", "-showsdks", capture_stdout=True)
    return [m.group(1) for m in re.finditer(r"-sdk (macosx\S+)", output)]
@@ -114,35 +140,44 @@ def get_python_configurations(
    return python_configurations


-def install_cpython(tmp: Path, version: str, url: str) -> Path:
-    installation_path = Path(f"/Library/Frameworks/Python.framework/Versions/{version}")
+def install_cpython(tmp: Path, version: str, url: str, free_threading: bool) -> Path:
+    ft = "T" if free_threading else ""
+    installation_path = Path(f"/Library/Frameworks/Python{ft}.framework/Versions/{version}")
    with FileLock(CIBW_CACHE_PATH / f"cpython{version}.lock"):
        installed_system_packages = call("pkgutil", "--pkgs", capture_stdout=True).splitlines()
        # if this version of python isn't installed, get it from python.org and install
-        python_package_identifier = f"org.python.Python.PythonFramework-{version}"
+        python_package_identifier = f"org.python.Python.Python{ft}Framework-{version}"
        if python_package_identifier not in installed_system_packages:
            if detect_ci_provider() is None:
                # if running locally, we don't want to install CPython with sudo
                # let the user know & provide a link to the installer
-                print(
+                msg = (
                    f"Error: CPython {version} is not installed.\n"
                    "cibuildwheel will not perform system-wide installs when running outside of CI.\n"
                    f"To build locally, install CPython {version} on this machine, or, disable this version of Python using CIBW_SKIP=cp{version.replace('.', '')}-macosx_*\n"
-                    f"\nDownload link: {url}",
-                    file=sys.stderr,
+                    f"\nDownload link: {url}"
                )
-                raise SystemExit(1)
+                raise errors.FatalError(msg)
            pkg_path = tmp / "Python.pkg"
            # download the pkg
            download(url, pkg_path)
            # install
-            call("sudo", "installer", "-pkg", pkg_path, "-target", "/")
+            args = []
+            if version.startswith("3.13"):
+                # Python 3.13 is the first version to have a free-threading option
+                args += ["-applyChoiceChangesXML", str(free_thread_enable_313.resolve())]
+            call("sudo", "installer", "-pkg", pkg_path, *args, "-target", "/")
            pkg_path.unlink()
            env = os.environ.copy()
            env["PIP_DISABLE_PIP_VERSION_CHECK"] = "1"
-            call(installation_path / "bin" / "python3", install_certifi_script, env=env)

-    return installation_path / "bin" / "python3"
+            if free_threading:
+                call(installation_path / f"bin/python{version}t", "-m", "ensurepip", env=env)
+                call(installation_path / f"bin/python{version}t", install_certifi_script, env=env)
+            else:
+                call(installation_path / "bin/python3", install_certifi_script, env=env)
+
+    return installation_path / "bin" / (f"python{version}t" if free_threading else "python3")


 def install_pypy(tmp: Path, url: str) -> Path:
@@ -166,22 +201,42 @@ def setup_python(
    dependency_constraint_flags: Sequence[PathOrStr],
    environment: ParsedEnvironment,
    build_frontend: BuildFrontendName,
-) -> dict[str, str]:
+) -> tuple[Path, dict[str, str]]:
+    if build_frontend == "build[uv]" and Version(python_configuration.version) < Version("3.8"):
+        build_frontend = "build"
+
+    uv_path = find_uv()
+    use_uv = build_frontend == "build[uv]" and Version(python_configuration.version) >= Version(
+        "3.8"
+    )
+
    tmp.mkdir()
    implementation_id = python_configuration.identifier.split("-")[0]
    log.step(f"Installing Python {implementation_id}...")
    if implementation_id.startswith("cp"):
-        base_python = install_cpython(tmp, python_configuration.version, python_configuration.url)
+        free_threading = "t-macos" in python_configuration.identifier
+        base_python = install_cpython(
+            tmp, python_configuration.version, python_configuration.url, free_threading
+        )
+
    elif implementation_id.startswith("pp"):
        base_python = install_pypy(tmp, python_configuration.url)
    else:
        msg = "Unknown Python implementation"
        raise ValueError(msg)
-    assert base_python.exists()
+    assert (
+        base_python.exists()
+    ), f"{base_python.name} not found, has {list(base_python.parent.iterdir())}"

    log.step("Setting up build environment...")
    venv_path = tmp / "venv"
-    env = virtualenv(base_python, venv_path, dependency_constraint_flags)
+    env = virtualenv(
+        python_configuration.version,
+        base_python,
+        venv_path,
+        dependency_constraint_flags,
+        use_uv=use_uv,
+    )
    venv_bin_path = venv_path / "bin"
    assert venv_bin_path.exists()
    # Fix issue with site.py setting the wrong `sys.prefix`, `sys.exec_prefix`,
@@ -197,43 +252,43 @@ def setup_python(

    # upgrade pip to the version matching our constraints
    # if necessary, reinstall it to ensure that it's available on PATH as 'pip'
-    call(
-        "python",
-        "-m",
-        "pip",
-        "install",
-        "--upgrade",
-        "pip",
-        *dependency_constraint_flags,
-        env=env,
-        cwd=venv_path,
-    )
+    if build_frontend == "build[uv]":
+        assert uv_path is not None
+        pip = [str(uv_path), "pip"]
+    else:
+        pip = ["python", "-m", "pip"]
+
+    if not use_uv:
+        call(
+            *pip,
+            "install",
+            "--upgrade",
+            "pip",
+            *dependency_constraint_flags,
+            env=env,
+            cwd=venv_path,
+        )

    # Apply our environment after pip is ready
    env = environment.as_dictionary(prev_environment=env)

    # check what pip version we're on
-    assert (venv_bin_path / "pip").exists()
-    call("which", "pip", env=env)
-    call("pip", "--version", env=env)
-    which_pip = call("which", "pip", env=env, capture_stdout=True).strip()
-    if which_pip != str(venv_bin_path / "pip"):
-        print(
-            "cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+    if not use_uv:
+        assert (venv_bin_path / "pip").exists()
+        call("which", "pip", env=env)
+        call("pip", "--version", env=env)
+        which_pip = call("which", "pip", env=env, capture_stdout=True).strip()
+        if which_pip != str(venv_bin_path / "pip"):
+            msg = "cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it."
+            raise errors.FatalError(msg)

    # check what Python version we're on
    call("which", "python", env=env)
    call("python", "--version", env=env)
    which_python = call("which", "python", env=env, capture_stdout=True).strip()
    if which_python != str(venv_bin_path / "python"):
-        print(
-            "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+        msg = "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it."
+        raise errors.FatalError(msg)

    config_is_arm64 = python_configuration.identifier.endswith("arm64")
    config_is_universal2 = python_configuration.identifier.endswith("universal2")
@@ -241,8 +296,25 @@ def setup_python(
    # Set MACOSX_DEPLOYMENT_TARGET, if the user didn't set it.
    # For arm64, the minimal deployment target is 11.0.
    # On x86_64 (or universal2), use 10.9 as a default.
-    # PyPy defaults to 10.7, causing inconsistencies if it's left unset.
-    env.setdefault("MACOSX_DEPLOYMENT_TARGET", "11.0" if config_is_arm64 else "10.9")
+    # CPython 3.13 needs 10.13.
+    if config_is_arm64:
+        default_target = "11.0"
+    elif Version(python_configuration.version) >= Version("3.13"):
+        default_target = "10.13"
+    elif python_configuration.identifier.startswith("pp") and Version(
+        python_configuration.version
+    ) >= Version("3.9"):
+        default_target = "10.15"
+    else:
+        default_target = "10.9"
+    env.setdefault("MACOSX_DEPLOYMENT_TARGET", default_target)
+
+    # This is a floor, it can't be set lower than the default_target.
+    if Version(env["MACOSX_DEPLOYMENT_TARGET"]) < Version(default_target):
+        log.warning(
+            f"Bumping MACOSX_DEPLOYMENT_TARGET ({env['MACOSX_DEPLOYMENT_TARGET']}) to the minimum required ({default_target})."
+        )
+        env["MACOSX_DEPLOYMENT_TARGET"] = default_target

    if python_configuration.version not in {"3.6", "3.7"}:
        if config_is_arm64:
@@ -301,10 +373,22 @@ def setup_python(
            *dependency_constraint_flags,
            env=env,
        )
+    elif build_frontend == "build[uv]":
+        assert uv_path is not None
+        call(
+            uv_path,
+            "pip",
+            "install",
+            "--upgrade",
+            "delocate",
+            "build[virtualenv, uv]",
+            *dependency_constraint_flags,
+            env=env,
+        )
    else:
        assert_never(build_frontend)

-    return env
+    return base_python, env


 def build(options: Options, tmp_path: Path) -> None:
@@ -333,6 +417,14 @@ def build(options: Options, tmp_path: Path) -> None:
        for config in python_configurations:
            build_options = options.build_options(config.identifier)
            build_frontend = build_options.build_frontend or BuildFrontendConfig("pip")
+            use_uv = build_frontend.name == "build[uv]" and Version(config.version) >= Version(
+                "3.8"
+            )
+            uv_path = find_uv()
+            if use_uv and uv_path is None:
+                msg = "uv not found"
+                raise AssertionError(msg)
+            pip = ["pip"] if not use_uv else [str(uv_path), "pip"]
            log.build_start(config.identifier)

            identifier_tmp_dir = tmp_path / config.identifier
@@ -350,13 +442,15 @@ def build(options: Options, tmp_path: Path) -> None:
                    build_options.dependency_constraints.get_for_python_version(config.version),
                ]

-            env = setup_python(
+            base_python, env = setup_python(
                identifier_tmp_dir / "build",
                config,
                dependency_constraint_flags,
                build_options.environment,
                build_frontend.name,
            )
+            if not use_uv:
+                pip_version = get_pip_version(env)

            compatible_wheel = find_compatible_wheel(built_wheels, config.identifier)
            if compatible_wheel:
@@ -381,6 +475,17 @@ def build(options: Options, tmp_path: Path) -> None:
                )
                extra_flags += build_frontend.args

+                build_env = env.copy()
+                if not use_uv:
+                    build_env["VIRTUALENV_PIP"] = pip_version
+                if build_options.dependency_constraints:
+                    constraint_path = build_options.dependency_constraints.get_for_python_version(
+                        config.version
+                    )
+                    combine_constraints(
+                        build_env, constraint_path, identifier_tmp_dir if use_uv else None
+                    )
+
                if build_frontend.name == "pip":
                    extra_flags += get_build_verbosity_extra_flags(build_options.build_verbosity)
                    # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
@@ -394,25 +499,14 @@ def build(options: Options, tmp_path: Path) -> None:
                        f"--wheel-dir={built_wheel_dir}",
                        "--no-deps",
                        *extra_flags,
-                        env=env,
+                        env=build_env,
                    )
-                elif build_frontend.name == "build":
+                elif build_frontend.name == "build" or build_frontend.name == "build[uv]":
                    if not 0 <= build_options.build_verbosity < 2:
                        msg = f"build_verbosity {build_options.build_verbosity} is not supported for build frontend. Ignoring."
                        log.warning(msg)
-                    build_env = env.copy()
-                    if build_options.dependency_constraints:
-                        constraint_path = (
-                            build_options.dependency_constraints.get_for_python_version(
-                                config.version
-                            )
-                        )
-                        user_constraints = build_env.get("PIP_CONSTRAINT")
-                        our_constraints = constraint_path.as_uri()
-                        build_env["PIP_CONSTRAINT"] = " ".join(
-                            c for c in [user_constraints, our_constraints] if c
-                        )
-                    build_env["VIRTUALENV_PIP"] = get_pip_version(env)
+                    if use_uv:
+                        extra_flags.append("--installer=uv")
                    call(
                        "python",
                        "-m",
@@ -542,15 +636,18 @@ def build(options: Options, tmp_path: Path) -> None:

                    # set up a virtual environment to install and test from, to make sure
                    # there are no dependencies that were pulled in at build time.
-                    call("pip", "install", "virtualenv", *dependency_constraint_flags, env=env)
+                    if not use_uv:
+                        call("pip", "install", "virtualenv", *dependency_constraint_flags, env=env)

                    venv_dir = identifier_tmp_dir / f"venv-test-{testing_arch}"

                    arch_prefix = []
+                    uv_arch_args = []
                    if testing_arch != machine_arch:
                        if machine_arch == "arm64" and testing_arch == "x86_64":
                            # rosetta2 will provide the emulation with just the arch prefix.
                            arch_prefix = ["arch", "-x86_64"]
+                            uv_arch_args = ["--python-platform", "x86_64-apple-darwin"]
                        else:
                            msg = f"don't know how to emulate {testing_arch} on {machine_arch}"
                            raise RuntimeError(msg)
@@ -559,17 +656,27 @@ def build(options: Options, tmp_path: Path) -> None:
                    call_with_arch = functools.partial(call, *arch_prefix)
                    shell_with_arch = functools.partial(call, *arch_prefix, "/bin/sh", "-c")

-                    # Use --no-download to ensure determinism by using seed libraries
-                    # built into virtualenv
-                    call_with_arch("python", "-m", "virtualenv", "--no-download", venv_dir, env=env)
+                    if use_uv:
+                        pip_install = functools.partial(call, *pip, "install", *uv_arch_args)
+                        call("uv", "venv", venv_dir, f"--python={base_python}", env=env)
+                    else:
+                        pip_install = functools.partial(call_with_arch, *pip, "install")
+                        # Use pip version from the initial env to ensure determinism
+                        venv_args = ["--no-periodic-update", f"--pip={pip_version}"]
+                        # In Python<3.12, setuptools & wheel are installed as well, use virtualenv embedded ones
+                        if Version(config.version) < Version("3.12"):
+                            venv_args.extend(("--setuptools=embed", "--wheel=embed"))
+                        call_with_arch("python", "-m", "virtualenv", *venv_args, venv_dir, env=env)

                    virtualenv_env = env.copy()
+                    virtualenv_env["MACOSX_DEPLOYMENT_TARGET"] = get_test_macosx_deployment_target()
                    virtualenv_env["PATH"] = os.pathsep.join(
                        [
                            str(venv_dir / "bin"),
                            virtualenv_env["PATH"],
                        ]
                    )
+                    virtualenv_env["VIRTUAL_ENV"] = str(venv_dir)

                    # check that we are using the Python from the virtual environment
                    call_with_arch("which", "python", env=virtualenv_env)
@@ -600,18 +707,14 @@ def build(options: Options, tmp_path: Path) -> None:
                    else:
                        virtualenv_env_install_wheel = virtualenv_env

-                    call_with_arch(
-                        "pip",
-                        "install",
+                    pip_install(
                        f"{repaired_wheel}{build_options.test_extras}",
                        env=virtualenv_env_install_wheel,
                    )

                    # test the wheel
                    if build_options.test_requires:
-                        call_with_arch(
-                            "pip",
-                            "install",
+                        pip_install(
                            *build_options.test_requires,
                            env=virtualenv_env_install_wheel,
                        )
@@ -634,18 +737,18 @@ def build(options: Options, tmp_path: Path) -> None:

            # we're all done here; move it to output (overwrite existing)
            if compatible_wheel is None:
-                with contextlib.suppress(FileNotFoundError):
-                    (build_options.output_dir / repaired_wheel.name).unlink()
-
-                shutil.move(str(repaired_wheel), build_options.output_dir)
-                built_wheels.append(build_options.output_dir / repaired_wheel.name)
+                output_wheel = build_options.output_dir.joinpath(repaired_wheel.name)
+                moved_wheel = move_file(repaired_wheel, output_wheel)
+                if moved_wheel != output_wheel.resolve():
+                    log.warning(
+                        "{repaired_wheel} was moved to {moved_wheel} instead of {output_wheel}"
+                    )
+                built_wheels.append(output_wheel)

            # clean up
            shutil.rmtree(identifier_tmp_dir)

            log.build_end()
    except subprocess.CalledProcessError as error:
-        log.step_end_with_error(
-            f"Command {error.cmd} failed with code {error.returncode}. {error.stdout}"
-        )
-        sys.exit(1)
+        msg = f"Command {error.cmd} failed with code {error.returncode}. {error.stdout or ''}"
+        raise errors.FatalError(msg) from error
@@ -11,7 +11,7 @@ import sys
 import typing
 import uuid
 from collections.abc import Mapping, Sequence
-from dataclasses import dataclass
+from dataclasses import dataclass, field
 from pathlib import Path, PurePath, PurePosixPath
 from types import TracebackType
 from typing import IO, Dict, Literal
@@ -32,7 +32,7 @@ ContainerEngineName = Literal["docker", "podman"]
@dataclass(frozen=True)
 class OCIContainerEngineConfig:
    name: ContainerEngineName
-    create_args: Sequence[str] = ()
+    create_args: tuple[str, ...] = field(default_factory=tuple)
    disable_host_mount: bool = False

    @staticmethod
@@ -58,7 +58,7 @@ class OCIContainerEngineConfig:
        )

        return OCIContainerEngineConfig(
-            name=name, create_args=create_args, disable_host_mount=disable_host_mount
+            name=name, create_args=tuple(create_args), disable_host_mount=disable_host_mount
        )

    def options_summary(self) -> str | dict[str, str]:
@@ -8,15 +8,14 @@ import difflib
 import enum
 import functools
 import shlex
-import sys
 import textwrap
-import traceback
 from collections.abc import Callable, Generator, Iterable, Iterator, Set
 from pathlib import Path
 from typing import Any, Literal, Mapping, Sequence, TypedDict, Union  # noqa: TID251

 from packaging.specifiers import SpecifierSet

+from . import errors
 from ._compat import tomllib
 from ._compat.typing import NotRequired, assert_never
 from .architecture import Architecture
@@ -52,6 +51,7 @@ class CommandLineArguments:
    print_build_identifiers: bool
    allow_empty: bool
    prerelease_pythons: bool
+    debug_traceback: bool

    @staticmethod
    def defaults() -> CommandLineArguments:
@@ -65,6 +65,7 @@ class CommandLineArguments:
            package_dir=Path("."),
            prerelease_pythons=False,
            print_build_identifiers=False,
+            debug_traceback=False,
        )


@@ -75,7 +76,6 @@ class GlobalOptions:
    build_selector: BuildSelector
    test_selector: TestSelector
    architectures: set[Architecture]
-    container_engine: OCIContainerEngineConfig


@dataclasses.dataclass(frozen=True)
@@ -95,6 +95,7 @@ class BuildOptions:
    build_verbosity: int
    build_frontend: BuildFrontendConfig | None
    config_settings: str
+    container_engine: OCIContainerEngineConfig

    @property
    def package_dir(self) -> Path:
@@ -117,7 +118,7 @@ class BuildOptions:
        return self.globals.architectures


-Setting = Union[Mapping[str, str], Sequence[str], str, int]
+Setting = Union[Mapping[str, str], Sequence[str], str, int, bool]


@dataclasses.dataclass(frozen=True)
@@ -196,7 +197,7 @@ def _resolve_cascade(
        if value is None:
            continue

-        if ignore_empty and not value:
+        if ignore_empty and not value and value is not False:
            continue

        value_string = _stringify_setting(value, list_sep, table_format)
@@ -215,6 +216,7 @@ def _resolve_cascade(
    return result


+# pylint: disable-next=inconsistent-return-statements
 def _merge_values(before: str | None, after: str, rule: InheritRule, merge_sep: str | None) -> str:
    if rule == InheritRule.NONE:
        return after
@@ -257,7 +259,7 @@ def _stringify_setting(
            raise ConfigOptionError(msg)
        return list_sep.join(setting)

-    if isinstance(setting, int):
+    if isinstance(setting, (bool, int)):
        return str(setting)

    return setting
@@ -515,6 +517,10 @@ class Options:
        skip_config = self.reader.get("skip", env_plat=False, list_sep=" ")
        test_skip = self.reader.get("test-skip", env_plat=False, list_sep=" ")

+        free_threaded_support = strtobool(
+            self.reader.get("free-threaded-support", env_plat=False, ignore_empty=True)
+        )
+
        prerelease_pythons = args.prerelease_pythons or strtobool(
            self.env.get("CIBW_PRERELEASE_PYTHONS", "0")
        )
@@ -535,34 +541,23 @@ class Options:
            skip_config = ""
            architectures = Architecture.all_archs(self.platform)
            prerelease_pythons = True
+            free_threaded_support = True

        build_selector = BuildSelector(
            build_config=build_config,
            skip_config=skip_config,
            requires_python=requires_python,
            prerelease_pythons=prerelease_pythons,
+            free_threaded_support=free_threaded_support,
        )
        test_selector = TestSelector(skip_config=test_skip)

-        container_engine_str = self.reader.get(
-            "container-engine",
-            table_format={"item": "{k}:{v}", "sep": "; ", "quote": shlex.quote},
-        )
-
-        try:
-            container_engine = OCIContainerEngineConfig.from_config_string(container_engine_str)
-        except ValueError as e:
-            msg = f"cibuildwheel: Failed to parse container config. {e}"
-            print(msg, file=sys.stderr)
-            sys.exit(2)
-
        return GlobalOptions(
            package_dir=package_dir,
            output_dir=output_dir,
            build_selector=build_selector,
            test_selector=test_selector,
            architectures=architectures,
-            container_engine=container_engine,
        )

    def build_options(self, identifier: str | None) -> BuildOptions:
@@ -603,18 +598,14 @@ class Options:
                try:
                    build_frontend = BuildFrontendConfig.from_config_string(build_frontend_str)
                except ValueError as e:
-                    print(f"cibuildwheel: {e}", file=sys.stderr)
-                    sys.exit(2)
+                    msg = f"Failed to parse build frontend. {e}"
+                    raise errors.ConfigurationError(msg) from e

            try:
                environment = parse_environment(environment_config)
-            except (EnvironmentParseError, ValueError):
-                print(
-                    f"cibuildwheel: Malformed environment option {environment_config!r}",
-                    file=sys.stderr,
-                )
-                traceback.print_exc(None, sys.stderr)
-                sys.exit(2)
+            except (EnvironmentParseError, ValueError) as e:
+                msg = f"Malformed environment option {environment_config!r}"
+                raise errors.ConfigurationError(msg) from e

            # Pass through environment variables
            if self.platform == "linux":
@@ -642,6 +633,8 @@ class Options:

            manylinux_images: dict[str, str] = {}
            musllinux_images: dict[str, str] = {}
+            container_engine: OCIContainerEngineConfig | None = None
+
            if self.platform == "linux":
                all_pinned_container_images = _get_pinned_container_images()

@@ -668,7 +661,7 @@ class Options:
                    config_value = self.reader.get(f"musllinux-{build_platform}-image")

                    if not config_value:
-                        image = pinned_images["musllinux_1_1"]
+                        image = pinned_images["musllinux_1_2"]
                    elif config_value in pinned_images:
                        image = pinned_images[config_value]
                    else:
@@ -676,6 +669,17 @@ class Options:

                    musllinux_images[build_platform] = image

+            container_engine_str = self.reader.get(
+                "container-engine",
+                table_format={"item": "{k}:{v}", "sep": "; ", "quote": shlex.quote},
+            )
+
+            try:
+                container_engine = OCIContainerEngineConfig.from_config_string(container_engine_str)
+            except ValueError as e:
+                msg = f"Failed to parse container config. {e}"
+                raise errors.ConfigurationError(msg) from e
+
            return BuildOptions(
                globals=self.globals,
                test_command=test_command,
@@ -692,6 +696,7 @@ class Options:
                musllinux_images=musllinux_images or None,
                build_frontend=build_frontend,
                config_settings=config_settings,
+                container_engine=container_engine,
            )

    def check_for_invalid_configuration(self, identifiers: Iterable[str]) -> None:
@@ -853,6 +858,6 @@ def _get_pinned_container_images() -> Mapping[str, Mapping[str, str]]:
 def deprecated_selectors(name: str, selector: str, *, error: bool = False) -> None:
    if "p2" in selector or "p35" in selector:
        msg = f"cibuildwheel 2.x no longer supports Python < 3.6. Please use the 1.x series or update {name}"
-        print(msg, file=sys.stderr)
        if error:
-            sys.exit(4)
+            raise errors.DeprecationError(msg)
+        log.warning(msg)
@@ -0,0 +1,404 @@
+from __future__ import annotations
+
+import os
+import shutil
+import sys
+from collections.abc import Sequence, Set
+from dataclasses import dataclass
+from pathlib import Path
+
+from filelock import FileLock
+
+from . import errors
+from .architecture import Architecture
+from .environment import ParsedEnvironment
+from .logger import log
+from .options import Options
+from .typing import PathOrStr
+from .util import (
+    CIBW_CACHE_PATH,
+    AlreadyBuiltWheelError,
+    BuildFrontendConfig,
+    BuildSelector,
+    NonPlatformWheelError,
+    call,
+    download,
+    ensure_node,
+    extract_zip,
+    find_compatible_wheel,
+    get_pip_version,
+    move_file,
+    prepare_command,
+    read_python_configs,
+    shell,
+    split_config_settings,
+    test_fail_cwd_file,
+    virtualenv,
+)
+
+
+@dataclass(frozen=True)
+class PythonConfiguration:
+    version: str
+    identifier: str
+    pyodide_version: str
+    emscripten_version: str
+    node_version: str
+
+
+def install_emscripten(tmp: Path, version: str) -> Path:
+    # We don't need to match the emsdk version to the version we install, but
+    # we do for stability
+    url = f"https://github.com/emscripten-core/emsdk/archive/refs/tags/{version}.zip"
+    installation_path = CIBW_CACHE_PATH / f"emsdk-{version}"
+    emsdk_path = installation_path / f"emsdk-{version}/emsdk"
+    emcc_path = installation_path / f"emsdk-{version}/upstream/emscripten/emcc"
+    with FileLock(f"{installation_path}.lock"):
+        if installation_path.exists():
+            return emcc_path
+        emsdk_zip = tmp / "emsdk.zip"
+        download(url, emsdk_zip)
+        installation_path.mkdir()
+        extract_zip(emsdk_zip, installation_path)
+        call(emsdk_path, "install", version)
+        call(emsdk_path, "activate", version)
+
+    return emcc_path
+
+
+def install_xbuildenv(env: dict[str, str], pyodide_version: str) -> str:
+    pyodide_root = (
+        CIBW_CACHE_PATH
+        / f".pyodide-xbuildenv-{pyodide_version}/{pyodide_version}/xbuildenv/pyodide-root"
+    )
+    with FileLock(CIBW_CACHE_PATH / "xbuildenv.lock"):
+        if pyodide_root.exists():
+            return str(pyodide_root)
+
+        # We don't want to mutate env but we need to delete any existing
+        # PYODIDE_ROOT so copy it first.
+        env = dict(env)
+        env.pop("PYODIDE_ROOT", None)
+        call(
+            "pyodide",
+            "xbuildenv",
+            "install",
+            pyodide_version,
+            env=env,
+            cwd=CIBW_CACHE_PATH,
+        )
+    return str(pyodide_root)
+
+
+def get_base_python(identifier: str) -> Path:
+    implementation_id = identifier.split("-")[0]
+    majorminor = implementation_id[len("cp") :]
+    version_info = (int(majorminor[0]), int(majorminor[1:]))
+    if version_info == sys.version_info[:2]:
+        return Path(sys.executable)
+
+    major_minor = ".".join(str(v) for v in version_info)
+    python_name = f"python{major_minor}"
+    which_python = shutil.which(python_name)
+    if which_python is None:
+        msg = f"CPython {major_minor} is not installed."
+        raise errors.FatalError(msg)
+    return Path(which_python)
+
+
+def setup_python(
+    tmp: Path,
+    python_configuration: PythonConfiguration,
+    dependency_constraint_flags: Sequence[PathOrStr],
+    environment: ParsedEnvironment,
+) -> dict[str, str]:
+    base_python = get_base_python(python_configuration.identifier)
+
+    log.step("Setting up build environment...")
+    venv_path = tmp / "venv"
+    env = virtualenv(python_configuration.version, base_python, venv_path, [], use_uv=False)
+    venv_bin_path = venv_path / "bin"
+    assert venv_bin_path.exists()
+    env["PIP_DISABLE_PIP_VERSION_CHECK"] = "1"
+
+    # upgrade pip to the version matching our constraints
+    # if necessary, reinstall it to ensure that it's available on PATH as 'pip'
+    call(
+        "python",
+        "-m",
+        "pip",
+        "install",
+        "--upgrade",
+        "pip",
+        *dependency_constraint_flags,
+        env=env,
+        cwd=venv_path,
+    )
+
+    env = environment.as_dictionary(prev_environment=env)
+
+    # check what pip version we're on
+    assert (venv_bin_path / "pip").exists()
+    call("which", "pip", env=env)
+    call("pip", "--version", env=env)
+    which_pip = call("which", "pip", env=env, capture_stdout=True).strip()
+    if which_pip != str(venv_bin_path / "pip"):
+        msg = "pip available on PATH doesn't match our venv instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it."
+        raise errors.FatalError(msg)
+
+    # check what Python version we're on
+    call("which", "python", env=env)
+    call("python", "--version", env=env)
+    which_python = call("which", "python", env=env, capture_stdout=True).strip()
+    if which_python != str(venv_bin_path / "python"):
+        msg = "python available on PATH doesn't match our venv instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it."
+        raise errors.FatalError(msg)
+
+    log.step("Installing build tools...")
+    call(
+        "pip",
+        "install",
+        "--upgrade",
+        "auditwheel-emscripten",
+        "build[virtualenv]",
+        "pyodide-build",
+        *dependency_constraint_flags,
+        env=env,
+    )
+
+    log.step("Installing emscripten...")
+    emcc_path = install_emscripten(tmp, python_configuration.emscripten_version)
+
+    env["PATH"] = os.pathsep.join([str(emcc_path.parent), env["PATH"]])
+
+    log.step("Installing Pyodide xbuildenv...")
+    env["PYODIDE_ROOT"] = install_xbuildenv(env, python_configuration.pyodide_version)
+
+    return env
+
+
+def get_python_configurations(
+    build_selector: BuildSelector,
+    architectures: Set[Architecture],  # noqa: ARG001
+) -> list[PythonConfiguration]:
+    full_python_configs = read_python_configs("pyodide")
+
+    python_configurations = [PythonConfiguration(**item) for item in full_python_configs]
+    python_configurations = [c for c in python_configurations if build_selector(c.identifier)]
+    return python_configurations
+
+
+def build(options: Options, tmp_path: Path) -> None:
+    python_configurations = get_python_configurations(
+        options.globals.build_selector, options.globals.architectures
+    )
+
+    if not python_configurations:
+        return
+
+    try:
+        before_all_options_identifier = python_configurations[0].identifier
+        before_all_options = options.build_options(before_all_options_identifier)
+
+        if before_all_options.before_all:
+            log.step("Running before_all...")
+            env = before_all_options.environment.as_dictionary(prev_environment=os.environ)
+            before_all_prepared = prepare_command(
+                before_all_options.before_all, project=".", package=before_all_options.package_dir
+            )
+            shell(before_all_prepared, env=env)
+
+        built_wheels: list[Path] = []
+
+        for config in python_configurations:
+            build_options = options.build_options(config.identifier)
+            build_frontend = build_options.build_frontend or BuildFrontendConfig("build")
+
+            if build_frontend.name == "pip":
+                msg = "The pyodide platform doesn't support pip frontend"
+                raise errors.FatalError(msg)
+
+            log.build_start(config.identifier)
+
+            identifier_tmp_dir = tmp_path / config.identifier
+            built_wheel_dir = identifier_tmp_dir / "built_wheel"
+            repaired_wheel_dir = identifier_tmp_dir / "repaired_wheel"
+            identifier_tmp_dir.mkdir()
+            built_wheel_dir.mkdir()
+            repaired_wheel_dir.mkdir()
+
+            dependency_constraint_flags: Sequence[PathOrStr] = []
+            if build_options.dependency_constraints:
+                constraints_path = build_options.dependency_constraints.get_for_python_version(
+                    config.version, variant="pyodide"
+                )
+                dependency_constraint_flags = ["-c", constraints_path]
+
+            env = setup_python(
+                identifier_tmp_dir / "build",
+                config,
+                dependency_constraint_flags,
+                build_options.environment,
+            )
+            pip_version = get_pip_version(env)
+            # The Pyodide command line runner mounts all directories in the host
+            # filesystem into the Pyodide file system, except for the custom
+            # file systems /dev, /lib, /proc, and /tmp. Mounting the mount
+            # points for alternate file systems causes some mysterious failure
+            # of the process (it just quits without any clear error).
+            #
+            # Because of this, by default Pyodide can't see anything under /tmp.
+            # This environment variable tells it also to mount our temp
+            # directory.
+            oldmounts = ""
+            extra_mounts = [str(identifier_tmp_dir)]
+            if str(Path(".").resolve()).startswith("/tmp"):
+                extra_mounts.append(str(Path(".").resolve()))
+
+            if "_PYODIDE_EXTRA_MOUNTS" in env:
+                oldmounts = env["_PYODIDE_EXTRA_MOUNTS"] + ":"
+            env["_PYODIDE_EXTRA_MOUNTS"] = oldmounts + ":".join(extra_mounts)
+
+            compatible_wheel = find_compatible_wheel(built_wheels, config.identifier)
+            if compatible_wheel:
+                log.step_end()
+                print(
+                    f"\nFound previously built wheel {compatible_wheel.name}, that's compatible with {config.identifier}. Skipping build step..."
+                )
+                built_wheel = compatible_wheel
+            else:
+                if build_options.before_build:
+                    log.step("Running before_build...")
+                    before_build_prepared = prepare_command(
+                        build_options.before_build, project=".", package=build_options.package_dir
+                    )
+                    shell(before_build_prepared, env=env)
+
+                log.step("Building wheel...")
+
+                extra_flags = split_config_settings(build_options.config_settings, "build")
+                extra_flags += build_frontend.args
+
+                if not 0 <= build_options.build_verbosity < 2:
+                    msg = f"build_verbosity {build_options.build_verbosity} is not supported for build frontend. Ignoring."
+                    log.warning(msg)
+
+                build_env = env.copy()
+                if build_options.dependency_constraints:
+                    our_constraints = str(constraints_path)
+                    user_constraints = build_env.get("PIP_CONSTRAINT")
+                    build_env["PIP_CONSTRAINT"] = " ".join(
+                        c for c in [our_constraints, user_constraints] if c
+                    )
+                build_env["VIRTUALENV_PIP"] = pip_version
+                call(
+                    "pyodide",
+                    "build",
+                    build_options.package_dir,
+                    f"--outdir={built_wheel_dir}",
+                    *extra_flags,
+                    env=build_env,
+                )
+                built_wheel = next(built_wheel_dir.glob("*.whl"))
+
+                if built_wheel.name.endswith("none-any.whl"):
+                    raise NonPlatformWheelError()
+
+                if build_options.repair_command:
+                    log.step("Repairing wheel...")
+
+                    repair_command_prepared = prepare_command(
+                        build_options.repair_command,
+                        wheel=built_wheel,
+                        dest_dir=repaired_wheel_dir,
+                    )
+                    shell(repair_command_prepared, env=env)
+                else:
+                    shutil.move(str(built_wheel), repaired_wheel_dir)
+
+                repaired_wheel = next(repaired_wheel_dir.glob("*.whl"))
+
+                if repaired_wheel.name in {wheel.name for wheel in built_wheels}:
+                    raise AlreadyBuiltWheelError(repaired_wheel.name)
+
+            if build_options.test_command and build_options.test_selector(config.identifier):
+                log.step("Testing wheel...")
+
+                venv_dir = identifier_tmp_dir / "venv-test"
+                # set up a virtual environment to install and test from, to make sure
+                # there are no dependencies that were pulled in at build time.
+
+                virtualenv_env = env.copy()
+                virtualenv_env["PATH"] = os.pathsep.join(
+                    [
+                        str(ensure_node(config.node_version)),
+                        virtualenv_env["PATH"],
+                    ]
+                )
+
+                # pyodide venv uses virtualenv under the hood
+                # use the pip embedded with virtualenv & disable network updates
+                virtualenv_create_env = virtualenv_env.copy()
+                virtualenv_create_env["VIRTUALENV_PIP"] = pip_version
+                virtualenv_create_env["VIRTUALENV_NO_PERIODIC_UPDATE"] = "1"
+
+                call("pyodide", "venv", venv_dir, env=virtualenv_create_env)
+
+                virtualenv_env["PATH"] = os.pathsep.join(
+                    [
+                        str(venv_dir / "bin"),
+                        virtualenv_env["PATH"],
+                    ]
+                )
+                virtualenv_env["VIRTUAL_ENV"] = str(venv_dir)
+
+                # check that we are using the Python from the virtual environment
+                call("which", "python", env=virtualenv_env)
+
+                if build_options.before_test:
+                    before_test_prepared = prepare_command(
+                        build_options.before_test,
+                        project=".",
+                        package=build_options.package_dir,
+                    )
+                    shell(before_test_prepared, env=virtualenv_env)
+
+                # install the wheel
+                call(
+                    "pip",
+                    "install",
+                    f"{repaired_wheel}{build_options.test_extras}",
+                    env=virtualenv_env,
+                )
+
+                # test the wheel
+                if build_options.test_requires:
+                    call("pip", "install", *build_options.test_requires, env=virtualenv_env)
+
+                # run the tests from a temp dir, with an absolute path in the command
+                # (this ensures that Python runs the tests against the installed wheel
+                # and not the repo code)
+                test_command_prepared = prepare_command(
+                    build_options.test_command,
+                    project=Path(".").resolve(),
+                    package=build_options.package_dir.resolve(),
+                )
+
+                test_cwd = identifier_tmp_dir / "test_cwd"
+                test_cwd.mkdir(exist_ok=True)
+                (test_cwd / "test_fail.py").write_text(test_fail_cwd_file.read_text())
+
+                shell(test_command_prepared, cwd=test_cwd, env=virtualenv_env)
+
+            # we're all done here; move it to output (overwrite existing)
+            if compatible_wheel is None:
+                output_wheel = build_options.output_dir.joinpath(repaired_wheel.name)
+                moved_wheel = move_file(repaired_wheel, output_wheel)
+                if moved_wheel != output_wheel.resolve():
+                    log.warning(
+                        "{repaired_wheel} was moved to {moved_wheel} instead of {output_wheel}"
+                    )
+                built_wheels.append(output_wheel)
+
+    finally:
+        pass
@@ -7,6 +7,8 @@ python_configurations = [
  { identifier = "cp310-manylinux_x86_64", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-manylinux_x86_64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-manylinux_x86_64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-manylinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-manylinux_i686", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-manylinux_i686", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-manylinux_i686", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -14,6 +16,8 @@ python_configurations = [
  { identifier = "cp310-manylinux_i686", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-manylinux_i686", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-manylinux_i686", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-manylinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "pp37-manylinux_x86_64", version = "3.7", path_str = "/opt/python/pp37-pypy37_pp73" },
  { identifier = "pp38-manylinux_x86_64", version = "3.8", path_str = "/opt/python/pp38-pypy38_pp73" },
  { identifier = "pp39-manylinux_x86_64", version = "3.9", path_str = "/opt/python/pp39-pypy39_pp73" },
@@ -25,6 +29,8 @@ python_configurations = [
  { identifier = "cp310-manylinux_aarch64", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-manylinux_aarch64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-manylinux_aarch64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-manylinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-manylinux_ppc64le", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-manylinux_ppc64le", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-manylinux_ppc64le", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -32,6 +38,8 @@ python_configurations = [
  { identifier = "cp310-manylinux_ppc64le", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-manylinux_ppc64le", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-manylinux_ppc64le", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-manylinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-manylinux_s390x", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-manylinux_s390x", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-manylinux_s390x", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -39,6 +47,8 @@ python_configurations = [
  { identifier = "cp310-manylinux_s390x", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-manylinux_s390x", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-manylinux_s390x", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-manylinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-manylinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "pp37-manylinux_aarch64", version = "3.7", path_str = "/opt/python/pp37-pypy37_pp73" },
  { identifier = "pp38-manylinux_aarch64", version = "3.8", path_str = "/opt/python/pp38-pypy38_pp73" },
  { identifier = "pp39-manylinux_aarch64", version = "3.9", path_str = "/opt/python/pp39-pypy39_pp73" },
@@ -54,6 +64,8 @@ python_configurations = [
  { identifier = "cp310-musllinux_x86_64", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-musllinux_x86_64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-musllinux_x86_64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-musllinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_x86_64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-musllinux_i686", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-musllinux_i686", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-musllinux_i686", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -61,6 +73,8 @@ python_configurations = [
  { identifier = "cp310-musllinux_i686", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-musllinux_i686", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-musllinux_i686", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-musllinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_i686", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-musllinux_aarch64", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-musllinux_aarch64", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-musllinux_aarch64", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -68,6 +82,8 @@ python_configurations = [
  { identifier = "cp310-musllinux_aarch64", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-musllinux_aarch64", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-musllinux_aarch64", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-musllinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_aarch64", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-musllinux_ppc64le", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-musllinux_ppc64le", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-musllinux_ppc64le", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -75,6 +91,8 @@ python_configurations = [
  { identifier = "cp310-musllinux_ppc64le", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-musllinux_ppc64le", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-musllinux_ppc64le", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-musllinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_ppc64le", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
  { identifier = "cp36-musllinux_s390x", version = "3.6", path_str = "/opt/python/cp36-cp36m" },
  { identifier = "cp37-musllinux_s390x", version = "3.7", path_str = "/opt/python/cp37-cp37m" },
  { identifier = "cp38-musllinux_s390x", version = "3.8", path_str = "/opt/python/cp38-cp38" },
@@ -82,6 +100,8 @@ python_configurations = [
  { identifier = "cp310-musllinux_s390x", version = "3.10", path_str = "/opt/python/cp310-cp310" },
  { identifier = "cp311-musllinux_s390x", version = "3.11", path_str = "/opt/python/cp311-cp311" },
  { identifier = "cp312-musllinux_s390x", version = "3.12", path_str = "/opt/python/cp312-cp312" },
+  { identifier = "cp313-musllinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313" },
+  { identifier = "cp313t-musllinux_s390x", version = "3.13", path_str = "/opt/python/cp313-cp313t" },
 ]

 [macos]
@@ -97,19 +117,25 @@ python_configurations = [
  { identifier = "cp310-macosx_x86_64", version = "3.10", url = "https://www.python.org/ftp/python/3.10.11/python-3.10.11-macos11.pkg" },
  { identifier = "cp310-macosx_arm64", version = "3.10", url = "https://www.python.org/ftp/python/3.10.11/python-3.10.11-macos11.pkg" },
  { identifier = "cp310-macosx_universal2", version = "3.10", url = "https://www.python.org/ftp/python/3.10.11/python-3.10.11-macos11.pkg" },
-  { identifier = "cp311-macosx_x86_64", version = "3.11", url = "https://www.python.org/ftp/python/3.11.8/python-3.11.8-macos11.pkg" },
-  { identifier = "cp311-macosx_arm64", version = "3.11", url = "https://www.python.org/ftp/python/3.11.8/python-3.11.8-macos11.pkg" },
-  { identifier = "cp311-macosx_universal2", version = "3.11", url = "https://www.python.org/ftp/python/3.11.8/python-3.11.8-macos11.pkg" },
-  { identifier = "cp312-macosx_x86_64", version = "3.12", url = "https://www.python.org/ftp/python/3.12.2/python-3.12.2-macos11.pkg" },
-  { identifier = "cp312-macosx_arm64", version = "3.12", url = "https://www.python.org/ftp/python/3.12.2/python-3.12.2-macos11.pkg" },
-  { identifier = "cp312-macosx_universal2", version = "3.12", url = "https://www.python.org/ftp/python/3.12.2/python-3.12.2-macos11.pkg" },
+  { identifier = "cp311-macosx_x86_64", version = "3.11", url = "https://www.python.org/ftp/python/3.11.9/python-3.11.9-macos11.pkg" },
+  { identifier = "cp311-macosx_arm64", version = "3.11", url = "https://www.python.org/ftp/python/3.11.9/python-3.11.9-macos11.pkg" },
+  { identifier = "cp311-macosx_universal2", version = "3.11", url = "https://www.python.org/ftp/python/3.11.9/python-3.11.9-macos11.pkg" },
+  { identifier = "cp312-macosx_x86_64", version = "3.12", url = "https://www.python.org/ftp/python/3.12.4/python-3.12.4-macos11.pkg" },
+  { identifier = "cp312-macosx_arm64", version = "3.12", url = "https://www.python.org/ftp/python/3.12.4/python-3.12.4-macos11.pkg" },
+  { identifier = "cp312-macosx_universal2", version = "3.12", url = "https://www.python.org/ftp/python/3.12.4/python-3.12.4-macos11.pkg" },
+  { identifier = "cp313-macosx_x86_64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
+  { identifier = "cp313-macosx_arm64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
+  { identifier = "cp313-macosx_universal2", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
+  { identifier = "cp313t-macosx_x86_64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
+  { identifier = "cp313t-macosx_arm64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
+  { identifier = "cp313t-macosx_universal2", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b2-macos11.pkg" },
  { identifier = "pp37-macosx_x86_64", version = "3.7", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.9-osx64.tar.bz2" },
  { identifier = "pp38-macosx_x86_64", version = "3.8", url = "https://downloads.python.org/pypy/pypy3.8-v7.3.11-macos_x86_64.tar.bz2" },
  { identifier = "pp38-macosx_arm64", version = "3.8", url = "https://downloads.python.org/pypy/pypy3.8-v7.3.11-macos_arm64.tar.bz2" },
-  { identifier = "pp39-macosx_x86_64", version = "3.9", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.15-macos_x86_64.tar.bz2" },
-  { identifier = "pp39-macosx_arm64", version = "3.9", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.15-macos_arm64.tar.bz2" },
-  { identifier = "pp310-macosx_x86_64", version = "3.10", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.15-macos_x86_64.tar.bz2" },
-  { identifier = "pp310-macosx_arm64", version = "3.10", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.15-macos_arm64.tar.bz2" },
+  { identifier = "pp39-macosx_x86_64", version = "3.9", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.16-macos_x86_64.tar.bz2" },
+  { identifier = "pp39-macosx_arm64", version = "3.9", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.16-macos_arm64.tar.bz2" },
+  { identifier = "pp310-macosx_x86_64", version = "3.10", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.16-macos_x86_64.tar.bz2" },
+  { identifier = "pp310-macosx_arm64", version = "3.10", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.16-macos_arm64.tar.bz2" },
 ]

 [windows]
@@ -124,16 +150,27 @@ python_configurations = [
  { identifier = "cp39-win_amd64", version = "3.9.13", arch = "64" },
  { identifier = "cp310-win32", version = "3.10.11", arch = "32" },
  { identifier = "cp310-win_amd64", version = "3.10.11", arch = "64" },
-  { identifier = "cp311-win32", version = "3.11.8", arch = "32" },
-  { identifier = "cp311-win_amd64", version = "3.11.8", arch = "64" },
-  { identifier = "cp312-win32", version = "3.12.2", arch = "32" },
-  { identifier = "cp312-win_amd64", version = "3.12.2", arch = "64" },
+  { identifier = "cp311-win32", version = "3.11.9", arch = "32" },
+  { identifier = "cp311-win_amd64", version = "3.11.9", arch = "64" },
+  { identifier = "cp312-win32", version = "3.12.4", arch = "32" },
+  { identifier = "cp312-win_amd64", version = "3.12.4", arch = "64" },
+  { identifier = "cp313-win32", version = "3.13.0-b2", arch = "32" },
+  { identifier = "cp313t-win32", version = "3.13.0-b2", arch = "32" },
+  { identifier = "cp313-win_amd64", version = "3.13.0-b2", arch = "64" },
+  { identifier = "cp313t-win_amd64", version = "3.13.0-b2", arch = "64" },
  { identifier = "cp39-win_arm64", version = "3.9.10", arch = "ARM64" },
  { identifier = "cp310-win_arm64", version = "3.10.11", arch = "ARM64" },
-  { identifier = "cp311-win_arm64", version = "3.11.8", arch = "ARM64" },
-  { identifier = "cp312-win_arm64", version = "3.12.2", arch = "ARM64" },
+  { identifier = "cp311-win_arm64", version = "3.11.9", arch = "ARM64" },
+  { identifier = "cp312-win_arm64", version = "3.12.4", arch = "ARM64" },
+  { identifier = "cp313-win_arm64", version = "3.13.0-b2", arch = "ARM64" },
+  { identifier = "cp313t-win_arm64", version = "3.13.0-b2", arch = "ARM64" },
  { identifier = "pp37-win_amd64", version = "3.7", arch = "64", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.9-win64.zip" },
  { identifier = "pp38-win_amd64", version = "3.8", arch = "64", url = "https://downloads.python.org/pypy/pypy3.8-v7.3.11-win64.zip" },
-  { identifier = "pp39-win_amd64", version = "3.9", arch = "64", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.15-win64.zip" },
-  { identifier = "pp310-win_amd64", version = "3.10", arch = "64", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.15-win64.zip" },
+  { identifier = "pp39-win_amd64", version = "3.9", arch = "64", url = "https://downloads.python.org/pypy/pypy3.9-v7.3.16-win64.zip" },
+  { identifier = "pp310-win_amd64", version = "3.10", arch = "64", url = "https://downloads.python.org/pypy/pypy3.10-v7.3.16-win64.zip" },
+]
+
+[pyodide]
+python_configurations = [
+  { identifier = "cp312-pyodide_wasm32", version = "3.12.1", pyodide_version = "0.26.1", emscripten_version = "3.1.58", node_version = "v20" },
 ]
@@ -1,10 +1,7 @@
 {
-  "$id": "https://github.com/pypa/cibuildwheel/blob/main/cibuildwheel/resources/cibuildwheel.schema.json",
  "$schema": "http://json-schema.org/draft-07/schema",
-  "additionalProperties": false,
-  "description": "cibuildwheel's settings.",
-  "type": "object",
-  "defines": {
+  "$id": "https://github.com/pypa/cibuildwheel/blob/main/cibuildwheel/resources/cibuildwheel.schema.json",
+  "$defs": {
    "inherit": {
      "enum": [
        "none",
@@ -15,6 +12,9 @@
      "description": "How to inherit the parent's value."
    }
  },
+  "additionalProperties": false,
+  "description": "cibuildwheel's settings.",
+  "type": "object",
  "properties": {
    "archs": {
      "description": "Change the architectures built on your machine by default.",
@@ -96,12 +96,13 @@
    },
    "build-frontend": {
      "default": "default",
-      "description": "Set the tool to use to build, either \"pip\" (default for now) or \"build\"",
+      "description": "Set the tool to use to build, either \"pip\" (default for now), \"build\", or \"build[uv]\"",
      "oneOf": [
        {
          "enum": [
            "pip",
            "build",
+            "build[uv]",
            "default"
          ]
        },
@@ -113,6 +114,10 @@
          "type": "string",
          "pattern": "^build; ?args:"
        },
+        {
+          "type": "string",
+          "pattern": "^build\\[uv\\]; ?args:"
+        },
        {
          "type": "object",
          "additionalProperties": false,
@@ -123,7 +128,8 @@
            "name": {
              "enum": [
                "pip",
-                "build"
+                "build",
+                "build[uv]"
              ]
            },
            "args": {
@@ -255,6 +261,12 @@
      ],
      "title": "CIBW_ENVIRONMENT_PASS"
    },
+    "free-threaded-support": {
+      "type": "boolean",
+      "default": false,
+      "description": "The project supports free-threaded builds of Python (PEP703)",
+      "title": "CIBW_FREE_THREADED_SUPPORT"
+    },
    "manylinux-aarch64-image": {
      "type": "string",
      "description": "Specify alternative manylinux / musllinux container images",
@@ -439,37 +451,37 @@
            "additionalProperties": false,
            "properties": {
              "before-all": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "before-build": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "before-test": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "config-settings": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "container-engine": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "environment": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "environment-pass": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "repair-wheel-command": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "test-command": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "test-extras": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              },
              "test-requires": {
-                "$ref": "#/defines/inherit"
+                "$ref": "#/$defs/inherit"
              }
            }
          },
@@ -491,6 +503,9 @@
          "config-settings": {
            "$ref": "#/properties/config-settings"
          },
+          "container-engine": {
+            "$ref": "#/properties/container-engine"
+          },
          "dependency-versions": {
            "$ref": "#/properties/dependency-versions"
          },
@@ -579,6 +594,9 @@
        "config-settings": {
          "$ref": "#/properties/config-settings"
        },
+        "container-engine": {
+          "$ref": "#/properties/container-engine"
+        },
        "environment": {
          "$ref": "#/properties/environment"
        },
@@ -753,6 +771,51 @@
          "$ref": "#/properties/test-requires"
        }
      }
+    },
+    "pyodide": {
+      "type": "object",
+      "additionalProperties": false,
+      "properties": {
+        "archs": {
+          "$ref": "#/properties/archs"
+        },
+        "before-all": {
+          "$ref": "#/properties/before-all"
+        },
+        "before-build": {
+          "$ref": "#/properties/before-build"
+        },
+        "before-test": {
+          "$ref": "#/properties/before-test"
+        },
+        "build-frontend": {
+          "$ref": "#/properties/build-frontend"
+        },
+        "build-verbosity": {
+          "$ref": "#/properties/build-verbosity"
+        },
+        "config-settings": {
+          "$ref": "#/properties/config-settings"
+        },
+        "dependency-versions": {
+          "$ref": "#/properties/dependency-versions"
+        },
+        "environment": {
+          "$ref": "#/properties/environment"
+        },
+        "repair-wheel-command": {
+          "$ref": "#/properties/repair-wheel-command"
+        },
+        "test-command": {
+          "$ref": "#/properties/test-command"
+        },
+        "test-extras": {
+          "$ref": "#/properties/test-extras"
+        },
+        "test-requires": {
+          "$ref": "#/properties/test-requires"
+        }
+      }
    }
  }
 }
@@ -0,0 +1,123 @@
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+annotated-types==0.7.0
+    # via pydantic
+anyio==4.4.0
+    # via httpx
+auditwheel-emscripten==0.0.14
+    # via pyodide-build
+build==1.2.1
+    # via
+    #   -r .nox/update_constraints/tmp/constraints-pyodide.in
+    #   pyodide-build
+certifi==2024.6.2
+    # via
+    #   httpcore
+    #   httpx
+    #   requests
+charset-normalizer==3.3.2
+    # via requests
+click==8.1.7
+    # via typer
+cloudpickle==3.0.0
+    # via loky
+cmake==3.29.5
+    # via pyodide-build
+distlib==0.3.8
+    # via virtualenv
+filelock==3.14.0
+    # via virtualenv
+h11==0.14.0
+    # via httpcore
+httpcore==1.0.5
+    # via httpx
+httpx==0.27.0
+    # via unearth
+idna==3.7
+    # via
+    #   anyio
+    #   httpx
+    #   requests
+leb128==1.0.7
+    # via auditwheel-emscripten
+loky==3.4.1
+    # via pyodide-build
+markdown-it-py==3.0.0
+    # via rich
+mdurl==0.1.2
+    # via markdown-it-py
+packaging==24.1
+    # via
+    #   auditwheel-emscripten
+    #   build
+    #   pyodide-build
+    #   unearth
+pip==24.0
+    # via -r .nox/update_constraints/tmp/constraints-pyodide.in
+platformdirs==4.2.2
+    # via virtualenv
+pydantic==2.7.4
+    # via
+    #   pyodide-build
+    #   pyodide-lock
+pydantic-core==2.18.4
+    # via pydantic
+pygments==2.18.0
+    # via rich
+pyodide-build==0.26.1
+    # via -r .nox/update_constraints/tmp/constraints-pyodide.in
+pyodide-cli==0.2.3
+    # via
+    #   auditwheel-emscripten
+    #   pyodide-build
+pyodide-lock==0.1.0a6
+    # via pyodide-build
+pyproject-hooks==1.1.0
+    # via build
+pyyaml==6.0.1
+    # via pyodide-build
+requests==2.32.3
+    # via pyodide-build
+resolvelib==1.0.1
+    # via pyodide-build
+rich==13.7.1
+    # via
+    #   pyodide-build
+    #   pyodide-cli
+    #   typer
+ruamel-yaml==0.18.6
+    # via pyodide-build
+ruamel-yaml-clib==0.2.8
+    # via ruamel-yaml
+shellingham==1.5.4
+    # via typer
+sniffio==1.3.1
+    # via
+    #   anyio
+    #   httpx
+typer==0.12.3
+    # via
+    #   auditwheel-emscripten
+    #   pyodide-build
+    #   pyodide-cli
+types-requests==2.32.0.20240602
+    # via pyodide-build
+typing-extensions==4.12.2
+    # via
+    #   pydantic
+    #   pydantic-core
+    #   typer
+unearth==0.15.4
+    # via pyodide-build
+urllib3==2.2.1
+    # via
+    #   requests
+    #   types-requests
+virtualenv==20.26.2
+    # via
+    #   build
+    #   pyodide-build
+wheel==0.43.0
+    # via
+    #   auditwheel-emscripten
+    #   pyodide-build
@@ -1,34 +1,34 @@
-#
-# This file is autogenerated by pip-compile with Python 3.10
-# by the following command:
-#
-#    nox -s update_constraints-3.10
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-packaging==24.0
+importlib-metadata==7.1.0
+    # via build
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-tomli==2.0.1
-    # via
-    #   build
-    #   pyproject-hooks
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+tomli==2.0.1
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
+zipp==3.19.2
+    # via importlib-metadata
@@ -1,30 +1,28 @@
-#
-# This file is autogenerated by pip-compile with Python 3.11
-# by the following command:
-#
-#    nox -s update_constraints-3.11
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-packaging==24.0
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
@@ -1,30 +1,28 @@
-#
-# This file is autogenerated by pip-compile with Python 3.12
-# by the following command:
-#
-#    nox -s update_constraints-3.12
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-packaging==24.0
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
@@ -0,0 +1,28 @@
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
+    # via -r cibuildwheel/resources/constraints.in
+delocate==0.11.0
+    # via -r cibuildwheel/resources/constraints.in
+distlib==0.3.8
+    # via virtualenv
+filelock==3.14.0
+    # via virtualenv
+macholib==1.16.3
+    # via delocate
+packaging==24.1
+    # via
+    #   build
+    #   delocate
+pip==24.1b2
+    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
@@ -48,3 +48,5 @@ zipp==3.6.0
 # The following packages are considered to be unsafe in a requirements file:
 pip==21.3.1
    # via -r cibuildwheel/resources/constraints.in
+setuptools==59.6.0
+    # via -r cibuildwheel/resources/constraints.in
@@ -1,12 +1,10 @@
-#
-# This file is autogenerated by pip-compile with Python 3.7
-# by the following command:
-#
-#    nox -s update_constraints-3.7
-#
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
 build==1.1.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
@@ -16,28 +14,26 @@ importlib-metadata==6.7.0
    # via
    #   build
    #   virtualenv
+macholib==1.16.3
+    # via delocate
 packaging==24.0
    # via
    #   build
    #   delocate
+pip==24.0
+    # via -r cibuildwheel/resources/constraints.in
 platformdirs==4.0.0
    # via virtualenv
-pyproject-hooks==1.0.0
+pyproject-hooks==1.1.0
    # via build
 tomli==2.0.1
-    # via
-    #   build
-    #   pyproject-hooks
+    # via build
 typing-extensions==4.7.1
    # via
    #   delocate
    #   importlib-metadata
    #   platformdirs
-virtualenv==20.25.1
+virtualenv==20.26.2
    # via -r cibuildwheel/resources/constraints.in
 zipp==3.15.0
    # via importlib-metadata
-
-# The following packages are considered to be unsafe in a requirements file:
-pip==24.0
-    # via -r cibuildwheel/resources/constraints.in
@@ -1,38 +1,34 @@
-#
-# This file is autogenerated by pip-compile with Python 3.8
-# by the following command:
-#
-#    nox -s update_constraints-3.8
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-importlib-metadata==7.0.2
+importlib-metadata==7.1.0
    # via build
-packaging==24.0
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-tomli==2.0.1
-    # via
-    #   build
-    #   pyproject-hooks
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-zipp==3.17.0
-    # via importlib-metadata
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+tomli==2.0.1
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
+zipp==3.19.2
+    # via importlib-metadata
@@ -1,38 +1,34 @@
-#
-# This file is autogenerated by pip-compile with Python 3.9
-# by the following command:
-#
-#    nox -s update_constraints-3.9
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-importlib-metadata==7.0.2
+importlib-metadata==7.1.0
    # via build
-packaging==24.0
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-tomli==2.0.1
-    # via
-    #   build
-    #   pyproject-hooks
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-zipp==3.17.0
-    # via importlib-metadata
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+tomli==2.0.1
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
+zipp==3.19.2
+    # via importlib-metadata
@@ -1,4 +1,5 @@
-pip
+pip>=24.1b1 ; python_version >= '3.13'
+pip ; python_version < '3.13'
 build
 delocate
 virtualenv
@@ -1,30 +1,28 @@
-#
-# This file is autogenerated by pip-compile with Python 3.12
-# by the following command:
-#
-#    nox -s update_constraints-3.12
-#
-build==1.1.1
+# This file was autogenerated by uv via the following command:
+#    nox -s update_constraints
+altgraph==0.17.4
+    # via macholib
+build==1.2.1
    # via -r cibuildwheel/resources/constraints.in
-delocate==0.10.7
+delocate==0.11.0
    # via -r cibuildwheel/resources/constraints.in
 distlib==0.3.8
    # via virtualenv
-filelock==3.13.1
+filelock==3.14.0
    # via virtualenv
-packaging==24.0
+macholib==1.16.3
+    # via delocate
+packaging==24.1
    # via
    #   build
    #   delocate
-platformdirs==4.2.0
-    # via virtualenv
-pyproject-hooks==1.0.0
-    # via build
-typing-extensions==4.10.0
-    # via delocate
-virtualenv==20.25.1
-    # via -r cibuildwheel/resources/constraints.in
-
-# The following packages are considered to be unsafe in a requirements file:
 pip==24.0
    # via -r cibuildwheel/resources/constraints.in
+platformdirs==4.2.2
+    # via virtualenv
+pyproject-hooks==1.1.0
+    # via build
+typing-extensions==4.12.2
+    # via delocate
+virtualenv==20.26.2
+    # via -r cibuildwheel/resources/constraints.in
@@ -2,6 +2,7 @@
 build = "*"
 skip = ""
 test-skip = ""
+free-threaded-support = false

 archs = ["auto"]
 build-frontend = "default"
@@ -31,11 +32,11 @@ manylinux-pypy_x86_64-image = "manylinux2014"
 manylinux-pypy_i686-image = "manylinux2014"
 manylinux-pypy_aarch64-image = "manylinux2014"

-musllinux-x86_64-image = "musllinux_1_1"
-musllinux-i686-image = "musllinux_1_1"
-musllinux-aarch64-image = "musllinux_1_1"
-musllinux-ppc64le-image = "musllinux_1_1"
-musllinux-s390x-image = "musllinux_1_1"
+musllinux-x86_64-image = "musllinux_1_2"
+musllinux-i686-image = "musllinux_1_2"
+musllinux-aarch64-image = "musllinux_1_2"
+musllinux-ppc64le-image = "musllinux_1_2"
+musllinux-s390x-image = "musllinux_1_2"


 [tool.cibuildwheel.linux]
@@ -45,3 +46,5 @@ repair-wheel-command = "auditwheel repair -w {dest_dir} {wheel}"
 repair-wheel-command = "delocate-wheel --require-archs {delocate_archs} -w {dest_dir} -v {wheel}"

 [tool.cibuildwheel.windows]
+
+[tool.cibuildwheel.pyodide]
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<array>
+        <dict>
+                <key>attributeSetting</key>
+                <integer>1</integer>
+                <key>choiceAttribute</key>
+                <string>selected</string>
+                <key>choiceIdentifier</key>
+                <string>org.python.Python.PythonTFramework-3.13</string>
+        </dict>
+</array>
+</plist>
@@ -0,0 +1,2 @@
+url = "https://nodejs.org/dist/"
+v20 = "v20.14.0"
@@ -1,54 +1,54 @@
 [x86_64]
-manylinux1 = quay.io/pypa/manylinux1_x86_64:2024-03-10-b85029d
+manylinux1 = quay.io/pypa/manylinux1_x86_64:2024-04-29-76807b8
 manylinux2010 = quay.io/pypa/manylinux2010_x86_64:2022-08-05-4535177
-manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_x86_64:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_x86_64:2024-03-10-4935fcc
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_x86_64:2024-03-10-4935fcc
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_x86_64:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_x86_64:2024.06.12-1
+musllinux_1_1 = quay.io/pypa/musllinux_1_1_x86_64:2024.06.12-1
+musllinux_1_2 = quay.io/pypa/musllinux_1_2_x86_64:2024.06.12-1

 [i686]
-manylinux1 = quay.io/pypa/manylinux1_i686:2024-03-10-b85029d
+manylinux1 = quay.io/pypa/manylinux1_i686:2024-04-29-76807b8
 manylinux2010 = quay.io/pypa/manylinux2010_i686:2022-08-05-4535177
-manylinux2014 = quay.io/pypa/manylinux2014_i686:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_i686:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_i686:2022-12-26-0d38463
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_i686:2024-03-10-4935fcc
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_i686:2024-03-10-4935fcc
+musllinux_1_1 = quay.io/pypa/musllinux_1_1_i686:2024.06.12-1
+musllinux_1_2 = quay.io/pypa/musllinux_1_2_i686:2024.06.12-1

 [pypy_x86_64]
 manylinux2010 = quay.io/pypa/manylinux2010_x86_64:2022-08-05-4535177
-manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_x86_64:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_x86_64:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_x86_64:2024.06.12-1

 [pypy_i686]
 manylinux2010 = quay.io/pypa/manylinux2010_i686:2022-08-05-4535177
-manylinux2014 = quay.io/pypa/manylinux2014_i686:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_i686:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_i686:2022-12-26-0d38463

 [aarch64]
-manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_aarch64:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_aarch64:2024-03-10-4935fcc
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_aarch64:2024-03-10-4935fcc
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_aarch64:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_aarch64:2024.06.12-1
+musllinux_1_1 = quay.io/pypa/musllinux_1_1_aarch64:2024.06.12-1
+musllinux_1_2 = quay.io/pypa/musllinux_1_2_aarch64:2024.06.12-1

 [ppc64le]
-manylinux2014 = quay.io/pypa/manylinux2014_ppc64le:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_ppc64le:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_ppc64le:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_ppc64le:2024-03-10-4935fcc
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_ppc64le:2024-03-10-4935fcc
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_ppc64le:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_ppc64le:2024.06.12-1
+musllinux_1_1 = quay.io/pypa/musllinux_1_1_ppc64le:2024.06.12-1
+musllinux_1_2 = quay.io/pypa/musllinux_1_2_ppc64le:2024.06.12-1

 [s390x]
-manylinux2014 = quay.io/pypa/manylinux2014_s390x:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_s390x:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_s390x:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_s390x:2024-03-10-4935fcc
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_s390x:2024-03-10-4935fcc
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_s390x:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_s390x:2024.06.12-1
+musllinux_1_1 = quay.io/pypa/musllinux_1_1_s390x:2024.06.12-1
+musllinux_1_2 = quay.io/pypa/musllinux_1_2_s390x:2024.06.12-1

 [pypy_aarch64]
-manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2024-03-10-4935fcc
+manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2024.06.12-1
 manylinux_2_24 = quay.io/pypa/manylinux_2_24_aarch64:2022-12-26-0d38463
-manylinux_2_28 = quay.io/pypa/manylinux_2_28_aarch64:2024-03-10-4935fcc
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_aarch64:2024.06.12-1

@@ -1,2 +1,2 @@
-version = "20.21.1"
-url = "https://github.com/pypa/get-virtualenv/blob/20.21.1/public/virtualenv.pyz?raw=true"
+py36 = { version = "20.21.1", url = "https://github.com/pypa/get-virtualenv/blob/20.21.1/public/virtualenv.pyz?raw=true" }
+default = { version = "20.26.2", url = "https://github.com/pypa/get-virtualenv/blob/20.26.2/public/virtualenv.pyz?raw=true" }
@@ -22,11 +22,10 @@ else:
    PathOrStr = Union[str, "os.PathLike[str]"]


-PlatformName = Literal["linux", "macos", "windows"]
-PLATFORMS: Final[set[PlatformName]] = {"linux", "macos", "windows"}
+PlatformName = Literal["linux", "macos", "windows", "pyodide"]
+PLATFORMS: Final[set[PlatformName]] = {"linux", "macos", "windows", "pyodide"}


 class GenericPythonConfiguration(Protocol):
    @property
-    def identifier(self) -> str:
-        ...
+    def identifier(self) -> str: ...
@@ -6,21 +6,25 @@ import itertools
 import os
 import re
 import shlex
+import shutil
 import ssl
 import subprocess
 import sys
+import tarfile
 import textwrap
 import time
 import typing
 import urllib.request
 from collections import defaultdict
-from collections.abc import Generator, Iterable, Mapping, Sequence
+from collections.abc import Generator, Iterable, Mapping, MutableMapping, Sequence
 from dataclasses import dataclass
 from enum import Enum
 from functools import cached_property, lru_cache
 from pathlib import Path, PurePath
+from tempfile import TemporaryDirectory
 from time import sleep
 from typing import Any, ClassVar, Final, Literal, TextIO, TypeVar
+from zipfile import ZipFile

 import bracex
 import certifi
@@ -32,29 +36,34 @@ from packaging.version import Version
 from platformdirs import user_cache_path

 from ._compat import tomllib
+from .architecture import Architecture
 from .typing import PathOrStr, PlatformName

 __all__ = [
-    "resources_dir",
    "MANYLINUX_ARCHS",
-    "call",
-    "shell",
-    "find_compatible_wheel",
-    "format_safe",
-    "prepare_command",
-    "get_build_verbosity_extra_flags",
-    "read_python_configs",
-    "selector_matches",
-    "strtobool",
    "cached_property",
+    "call",
    "chdir",
+    "combine_constraints",
+    "find_compatible_wheel",
+    "find_uv",
+    "format_safe",
+    "get_build_verbosity_extra_flags",
+    "prepare_command",
+    "read_python_configs",
+    "resources_dir",
+    "selector_matches",
+    "shell",
    "split_config_settings",
+    "strtobool",
 ]

 resources_dir: Final[Path] = Path(__file__).parent / "resources"

 install_certifi_script: Final[Path] = resources_dir / "install_certifi.py"

+free_thread_enable_313: Final[Path] = resources_dir / "free-threaded-enable-313.xml"
+
 test_fail_cwd_file: Final[Path] = resources_dir / "testing_temp_dir_file.py"


@@ -91,8 +100,7 @@ def call(
    env: Mapping[str, str] | None = None,
    cwd: PathOrStr | None = None,
    capture_stdout: Literal[False] = ...,
-) -> None:
-    ...
+) -> None: ...


@typing.overload
@@ -101,8 +109,7 @@ def call(
    env: Mapping[str, str] | None = None,
    cwd: PathOrStr | None = None,
    capture_stdout: Literal[True],
-) -> str:
-    ...
+) -> str: ...


 def call(
@@ -197,7 +204,9 @@ def get_build_verbosity_extra_flags(level: int) -> list[str]:
        return []


-def split_config_settings(config_settings: str, frontend: Literal["pip", "build"]) -> list[str]:
+def split_config_settings(
+    config_settings: str, frontend: Literal["pip", "build", "build[uv]"]
+) -> list[str]:
    config_settings_list = shlex.split(config_settings)
    s = "s" if frontend == "pip" else ""
    return [f"--config-setting{s}={setting}" for setting in config_settings_list]
@@ -240,13 +249,17 @@ class BuildSelector:
    requires_python: SpecifierSet | None = None

    # a pattern that skips prerelease versions, when include_prereleases is False.
-    PRERELEASE_SKIP: ClassVar[str] = ""
+    PRERELEASE_SKIP: ClassVar[str] = "cp313-* cp313t-*"
    prerelease_pythons: bool = False

+    free_threaded_support: bool = False
+
    def __call__(self, build_id: str) -> bool:
        # Filter build selectors by python_requires if set
        if self.requires_python is not None:
            py_ver_str = build_id.split("-")[0]
+            if py_ver_str.endswith("t"):
+                py_ver_str = py_ver_str[:-1]
            major = int(py_ver_str[2])
            minor = int(py_ver_str[3:])
            version = Version(f"{major}.{minor}.99")
@@ -257,6 +270,10 @@ class BuildSelector:
        if not self.prerelease_pythons and selector_matches(self.PRERELEASE_SKIP, build_id):
            return False

+        # filter out free threaded pythons if self.free_threaded_support is False
+        if not self.free_threaded_support and selector_matches("*t-*", build_id):
+            return False
+
        should_build = selector_matches(self.build_config, build_id)
        should_skip = selector_matches(self.skip_config, build_id)

@@ -268,6 +285,7 @@ class BuildSelector:
            "skip_config": self.skip_config,
            "requires_python": str(self.requires_python),
            "prerelease_pythons": self.prerelease_pythons,
+            "free_threaded_support": self.free_threaded_support,
        }


@@ -327,6 +345,55 @@ def download(url: str, dest: Path) -> None:
            sleep(3)


+def extract_zip(zip_src: Path, dest: Path) -> None:
+    with ZipFile(zip_src) as zip_:
+        for zinfo in zip_.filelist:
+            zip_.extract(zinfo, dest)
+
+            # Set permissions to the same values as they were set in the archive
+            # We have to do this manually due to
+            # https://github.com/python/cpython/issues/59999
+            # But some files in the zipfile seem to have external_attr with 0
+            # permissions. In that case just use the default value???
+            permissions = (zinfo.external_attr >> 16) & 0o777
+            if permissions != 0:
+                dest.joinpath(zinfo.filename).chmod(permissions)
+
+
+def extract_tar(tar_src: Path, dest: Path) -> None:
+    with tarfile.open(tar_src) as tar_:
+        tar_.extraction_filter = getattr(tarfile, "tar_filter", (lambda member, _: member))
+        tar_.extractall(dest)
+
+
+def move_file(src_file: Path, dst_file: Path) -> Path:
+    """Moves a file safely while avoiding potential semantic confusion:
+
+    1. `dst_file` must point to the target filename, not a directory
+    2. `dst_file` will be overwritten if it already exists
+    3. any missing parent directories will be created
+
+    Returns the fully resolved Path of the resulting file.
+
+    Raises:
+        NotADirectoryError: If any part of the intermediate path to `dst_file` is an existing file
+        IsADirectoryError: If `dst_file` points directly to an existing directory
+    """
+    src_file = src_file.resolve(strict=True)
+    dst_file = dst_file.resolve()
+
+    if dst_file.is_dir():
+        msg = "dst_file must be a valid target filename, not an existing directory."
+        raise IsADirectoryError(msg)
+    dst_file.unlink(missing_ok=True)
+    dst_file.parent.mkdir(parents=True, exist_ok=True)
+
+    # using shutil.move() as Path.rename() is not guaranteed to work across filesystem boundaries
+    # explicit str() needed for Python 3.8
+    resulting_file = shutil.move(str(src_file), str(dst_file))
+    return Path(resulting_file).resolve(strict=True)
+
+
 class DependencyConstraints:
    def __init__(self, base_file_path: Path):
        assert base_file_path.exists()
@@ -336,12 +403,14 @@ class DependencyConstraints:
    def with_defaults() -> DependencyConstraints:
        return DependencyConstraints(base_file_path=resources_dir / "constraints.txt")

-    def get_for_python_version(self, version: str) -> Path:
+    def get_for_python_version(
+        self, version: str, *, variant: Literal["python", "pyodide"] = "python"
+    ) -> Path:
        version_parts = version.split(".")

        # try to find a version-specific dependency file e.g. if
        # ./constraints.txt is the base, look for ./constraints-python36.txt
-        specific_stem = self.base_file_path.stem + f"-python{version_parts[0]}{version_parts[1]}"
+        specific_stem = self.base_file_path.stem + f"-{variant}{version_parts[0]}{version_parts[1]}"
        specific_name = specific_stem + self.base_file_path.suffix
        specific_file_path = self.base_file_path.with_name(specific_name)

@@ -366,7 +435,7 @@ class DependencyConstraints:
            return self.base_file_path.name


-BuildFrontendName = Literal["pip", "build"]
+BuildFrontendName = Literal["pip", "build", "build[uv]"]


@dataclass(frozen=True)
@@ -378,8 +447,8 @@ class BuildFrontendConfig:
    def from_config_string(config_string: str) -> BuildFrontendConfig:
        config_dict = parse_key_value_string(config_string, ["name"], ["args"])
        name = " ".join(config_dict["name"])
-        if name not in {"pip", "build"}:
-            msg = f"Unrecognised build frontend {name}, only 'pip' and 'build' are supported"
+        if name not in {"pip", "build", "build[uv]"}:
+            msg = f"Unrecognised build frontend {name!r}, only 'pip', 'build', and 'build[uv]' are supported"
            raise ValueError(msg)

        name = typing.cast(BuildFrontendName, name)
@@ -528,12 +597,47 @@ def get_pip_version(env: Mapping[str, str]) -> str:


@lru_cache(maxsize=None)
-def _ensure_virtualenv() -> Path:
+def ensure_node(major_version: str) -> Path:
+    input_file = resources_dir / "nodejs.toml"
+    with input_file.open("rb") as f:
+        loaded_file = tomllib.load(f)
+    version = str(loaded_file[major_version])
+    base_url = str(loaded_file["url"])
+    ext = "zip" if IS_WIN else "tar.xz"
+    platform = "win" if IS_WIN else ("darwin" if sys.platform.startswith("darwin") else "linux")
+    linux_arch = Architecture.native_arch("linux")
+    assert linux_arch is not None
+    arch = {"x86_64": "x64", "i686": "x86", "aarch64": "arm64"}.get(
+        linux_arch.value, linux_arch.value
+    )
+    name = f"node-{version}-{platform}-{arch}"
+    path = CIBW_CACHE_PATH / name
+    with FileLock(str(path) + ".lock"):
+        if not path.exists():
+            url = f"{base_url}{version}/{name}.{ext}"
+            with TemporaryDirectory() as tmp_path:
+                archive = Path(tmp_path) / f"{name}.{ext}"
+                download(url, archive)
+                if ext == "zip":
+                    extract_zip(archive, path.parent)
+                else:
+                    extract_tar(archive, path.parent)
+    assert path.exists()
+    if not IS_WIN:
+        return path / "bin"
+    return path
+
+
+@lru_cache(maxsize=None)
+def _ensure_virtualenv(version: str) -> Path:
+    version_parts = version.split(".")
+    key = f"py{version_parts[0]}{version_parts[1]}"
    input_file = resources_dir / "virtualenv.toml"
    with input_file.open("rb") as f:
        loaded_file = tomllib.load(f)
-    version = str(loaded_file["version"])
-    url = str(loaded_file["url"])
+    configuration = loaded_file.get(key, loaded_file["default"])
+    version = str(configuration["version"])
+    url = str(configuration["url"])
    path = CIBW_CACHE_PATH / f"virtualenv-{version}.pyz"
    with FileLock(str(path) + ".lock"):
        if not path.exists():
@@ -542,6 +646,7 @@ def _ensure_virtualenv() -> Path:


 def _parse_constraints_for_virtualenv(
+    seed_packages: list[str],
    dependency_constraint_flags: Sequence[PathOrStr],
 ) -> dict[str, str]:
    """
@@ -554,8 +659,8 @@ def _parse_constraints_for_virtualenv(
    {macos|windows}.setup_python function.
    """
    assert len(dependency_constraint_flags) in {0, 2}
-    packages = ["pip", "setuptools", "wheel"]
-    constraints_dict = {package: "embed" for package in packages}
+    # only seed pip if other seed packages do not appear in a constraint file
+    constraints_dict = {"pip": "embed"}
    if len(dependency_constraint_flags) == 2:
        assert dependency_constraint_flags[0] == "-c"
        constraint_path = Path(dependency_constraint_flags[1])
@@ -571,7 +676,7 @@ def _parse_constraints_for_virtualenv(
                    requirement = Requirement(line)
                    package = requirement.name
                    if (
-                        package not in packages
+                        package not in seed_packages
                        or requirement.url is not None
                        or requirement.marker is not None
                        or len(requirement.extras) != 0
@@ -588,40 +693,64 @@ def _parse_constraints_for_virtualenv(


 def virtualenv(
-    python: Path, venv_path: Path, dependency_constraint_flags: Sequence[PathOrStr]
+    version: str,
+    python: Path,
+    venv_path: Path,
+    dependency_constraint_flags: Sequence[PathOrStr],
+    *,
+    use_uv: bool,
 ) -> dict[str, str]:
+    """
+    Create a virtual environment. If `use_uv` is True,
+    dependency_constraint_flags are ignored since nothing is installed in the
+    venv. Otherwise, pip is installed, and setuptools + wheel if Python < 3.12.
+    """
    assert python.exists()
-    virtualenv_app = _ensure_virtualenv()
-    constraints = _parse_constraints_for_virtualenv(dependency_constraint_flags)
-    additional_flags = [f"--{package}={version}" for package, version in constraints.items()]

-    # Using symlinks to pre-installed seed packages is really the fastest way to get a virtual
-    # environment. The initial cost is a bit higher but reusing is much faster.
-    # Windows does not always allow symlinks so just disabling for now.
-    # Requires pip>=19.3 so disabling for "embed" because this means we don't know what's the
-    # version of pip that will end-up installed.
-    # c.f. https://virtualenv.pypa.io/en/latest/cli_interface.html#section-seeder
-    if (
-        not IS_WIN
-        and constraints["pip"] != "embed"
-        and Version(constraints["pip"]) >= Version("19.3")
-    ):
-        additional_flags.append("--symlink-app-data")
+    if use_uv:
+        call("uv", "venv", venv_path, "--python", python)
+    else:
+        virtualenv_app = _ensure_virtualenv(version)
+        allowed_seed_packages = ["pip", "setuptools", "wheel"]
+        constraints = _parse_constraints_for_virtualenv(
+            allowed_seed_packages, dependency_constraint_flags
+        )
+        additional_flags: list[str] = []
+        for package in allowed_seed_packages:
+            if package in constraints:
+                additional_flags.append(f"--{package}={constraints[package]}")
+            else:
+                additional_flags.append(f"--no-{package}")
+
+        # Using symlinks to pre-installed seed packages is really the fastest way to get a virtual
+        # environment. The initial cost is a bit higher but reusing is much faster.
+        # Windows does not always allow symlinks so just disabling for now.
+        # Requires pip>=19.3 so disabling for "embed" because this means we don't know what's the
+        # version of pip that will end-up installed.
+        # c.f. https://virtualenv.pypa.io/en/latest/cli_interface.html#section-seeder
+        if (
+            not IS_WIN
+            and constraints["pip"] != "embed"
+            and Version(constraints["pip"]) >= Version("19.3")
+        ):
+            additional_flags.append("--symlink-app-data")
+
+        call(
+            sys.executable,
+            "-sS",  # just the stdlib, https://github.com/pypa/virtualenv/issues/2133#issuecomment-1003710125
+            virtualenv_app,
+            "--activators=",
+            "--no-periodic-update",
+            *additional_flags,
+            "--python",
+            python,
+            venv_path,
+        )

-    call(
-        sys.executable,
-        "-sS",  # just the stdlib, https://github.com/pypa/virtualenv/issues/2133#issuecomment-1003710125
-        virtualenv_app,
-        "--activators=",
-        "--no-periodic-update",
-        *additional_flags,
-        "--python",
-        python,
-        venv_path,
-    )
    paths = [str(venv_path), str(venv_path / "Scripts")] if IS_WIN else [str(venv_path / "bin")]
    env = os.environ.copy()
    env["PATH"] = os.pathsep.join([*paths, env["PATH"]])
+    env["VIRTUAL_ENV"] = str(venv_path)
    return env


@@ -635,10 +764,13 @@ def find_compatible_wheel(wheels: Sequence[T], identifier: str) -> T | None:
    """

    interpreter, platform = identifier.split("-")
+    free_threaded = interpreter.endswith("t")
+    if free_threaded:
+        interpreter = interpreter[:-1]
    for wheel in wheels:
        _, _, _, tags = parse_wheel_filename(wheel.name)
        for tag in tags:
-            if tag.abi == "abi3":
+            if tag.abi == "abi3" and not free_threaded:
                # ABI3 wheels must start with cp3 for impl and tag
                if not (interpreter.startswith("cp3") and tag.interpreter.startswith("cp3")):
                    continue
@@ -760,3 +892,42 @@ def parse_key_value_string(
        result[field_name] += values

    return dict(result)
+
+
+def find_uv() -> Path | None:
+    # Prefer uv in our environment
+    with contextlib.suppress(ImportError, FileNotFoundError):
+        # pylint: disable-next=import-outside-toplevel
+        from uv import find_uv_bin
+
+        return Path(find_uv_bin())
+
+    uv_on_path = shutil.which("uv")
+    return Path(uv_on_path) if uv_on_path else None
+
+
+def combine_constraints(
+    env: MutableMapping[str, str], /, constraints_path: Path, tmp_dir: Path | None
+) -> None:
+    """
+    This will workaround a bug in pip<=21.1.1 or uv<=0.2.0 if a tmp_dir is given.
+    If set to None, this will use the modern URI method.
+    """
+
+    if tmp_dir:
+        if " " in str(constraints_path):
+            assert " " not in str(tmp_dir)
+            tmp_file = tmp_dir / "constraints.txt"
+            tmp_file.write_bytes(constraints_path.read_bytes())
+            constraints_path = tmp_file
+        our_constraints = str(constraints_path)
+    else:
+        our_constraints = (
+            constraints_path.as_uri() if " " in str(constraints_path) else str(constraints_path)
+        )
+
+    user_constraints = env.get("PIP_CONSTRAINT")
+
+    env["UV_CONSTRAINT"] = env["PIP_CONSTRAINT"] = " ".join(
+        c for c in [our_constraints, user_constraints] if c
+    )
@@ -4,18 +4,16 @@ import os
 import platform as platform_module
 import shutil
 import subprocess
-import sys
 import textwrap
 from collections.abc import MutableMapping, Sequence, Set
-from contextlib import suppress
 from dataclasses import dataclass
 from functools import lru_cache
 from pathlib import Path
-from zipfile import ZipFile

 from filelock import FileLock
 from packaging.version import Version

+from . import errors
 from ._compat.typing import assert_never
 from .architecture import Architecture
 from .environment import ParsedEnvironment
@@ -30,10 +28,14 @@ from .util import (
    BuildSelector,
    NonPlatformWheelError,
    call,
+    combine_constraints,
    download,
+    extract_zip,
    find_compatible_wheel,
+    find_uv,
    get_build_verbosity_extra_flags,
    get_pip_version,
+    move_file,
    prepare_command,
    read_python_configs,
    shell,
@@ -44,7 +46,9 @@ from .util import (
 )


-def get_nuget_args(version: str, arch: str, output_directory: Path) -> list[str]:
+def get_nuget_args(
+    version: str, arch: str, free_threaded: bool, output_directory: Path
+) -> list[str]:
    package_name = {
        "32": "pythonx86",
        "64": "python",
@@ -53,6 +57,8 @@ def get_nuget_args(version: str, arch: str, output_directory: Path) -> list[str]
        "x86": "pythonx86",
        "AMD64": "python",
    }[arch]
+    if free_threaded:
+        package_name = f"{package_name}-freethreaded"
    return [
        package_name,
        "-Version",
@@ -92,11 +98,6 @@ def get_python_configurations(
    return python_configurations


-def extract_zip(zip_src: Path, dest: Path) -> None:
-    with ZipFile(zip_src) as zip_:
-        zip_.extractall(dest)
-
-
@lru_cache(maxsize=None)
 def _ensure_nuget() -> Path:
    nuget = CIBW_CACHE_PATH / "nuget.exe"
@@ -106,11 +107,16 @@ def _ensure_nuget() -> Path:
    return nuget


-def install_cpython(version: str, arch: str) -> Path:
+def install_cpython(configuration: PythonConfiguration, arch: str | None = None) -> Path:
+    version = configuration.version
+    free_threaded = "t-" in configuration.identifier
+    if arch is None:
+        arch = configuration.arch
    base_output_dir = CIBW_CACHE_PATH / "nuget-cpython"
-    nuget_args = get_nuget_args(version, arch, base_output_dir)
+    nuget_args = get_nuget_args(version, arch, free_threaded, base_output_dir)
    installation_path = base_output_dir / (nuget_args[0] + "." + version) / "tools"
-    with FileLock(str(base_output_dir) + f"-{version}-{arch}.lock"):
+    free_threaded_str = "-freethreaded" if free_threaded else ""
+    with FileLock(str(base_output_dir) + f"-{version}{free_threaded_str}-{arch}.lock"):
        if not installation_path.exists():
            nuget = _ensure_nuget()
            call(nuget, "install", *nuget_args)
@@ -217,25 +223,21 @@ def setup_python(
    dependency_constraint_flags: Sequence[PathOrStr],
    environment: ParsedEnvironment,
    build_frontend: BuildFrontendName,
-) -> dict[str, str]:
+) -> tuple[Path, dict[str, str]]:
    tmp.mkdir()
    implementation_id = python_configuration.identifier.split("-")[0]
    python_libs_base = None
    log.step(f"Installing Python {implementation_id}...")
    if implementation_id.startswith("cp"):
        native_arch = platform_module.machine()
+        base_python = install_cpython(python_configuration)
        if python_configuration.arch == "ARM64" != native_arch:
            # To cross-compile for ARM64, we need a native CPython to run the
            # build, and a copy of the ARM64 import libraries ('.\libs\*.lib')
            # for any extension modules.
-            python_libs_base = install_cpython(
-                python_configuration.version, python_configuration.arch
-            )
-            python_libs_base = python_libs_base.parent / "libs"
+            python_libs_base = base_python.parent / "libs"
            log.step(f"Installing native Python {native_arch} for cross-compilation...")
-            base_python = install_cpython(python_configuration.version, native_arch)
-        else:
-            base_python = install_cpython(python_configuration.version, python_configuration.arch)
+            base_python = install_cpython(python_configuration, arch=native_arch)
    elif implementation_id.startswith("pp"):
        assert python_configuration.url is not None
        base_python = install_pypy(tmp, python_configuration.arch, python_configuration.url)
@@ -244,28 +246,34 @@ def setup_python(
        raise ValueError(msg)
    assert base_python.exists()

+    use_uv = build_frontend == "build[uv]" and Version(python_configuration.version) >= Version(
+        "3.8"
+    )
+    uv_path = find_uv()
+
    log.step("Setting up build environment...")
    venv_path = tmp / "venv"
-    env = virtualenv(base_python, venv_path, dependency_constraint_flags)
+    env = virtualenv(
+        python_configuration.version,
+        base_python,
+        venv_path,
+        dependency_constraint_flags,
+        use_uv=use_uv,
+    )

    # set up environment variables for run_with_env
    env["PYTHON_VERSION"] = python_configuration.version
    env["PYTHON_ARCH"] = python_configuration.arch
    env["PIP_DISABLE_PIP_VERSION_CHECK"] = "1"

-    # pip older than 21.3 builds executables such as pip.exe for x64 platform.
-    # The first re-install of pip updates pip module but builds pip.exe using
-    # the old pip which still generates x64 executable. But the second
-    # re-install uses updated pip and correctly builds pip.exe for the target.
-    # This can be removed once ARM64 Pythons (currently 3.9 and 3.10) bundle
-    # pip versions newer than 21.3.
-    if python_configuration.arch == "ARM64" and Version(get_pip_version(env)) < Version("21.3"):
+    # upgrade pip to the version matching our constraints
+    # if necessary, reinstall it to ensure that it's available on PATH as 'pip.exe'
+    if not use_uv:
        call(
            "python",
            "-m",
            "pip",
            "install",
-            "--force-reinstall",
            "--upgrade",
            "pip",
            *dependency_constraint_flags,
@@ -273,20 +281,6 @@ def setup_python(
            cwd=venv_path,
        )

-    # upgrade pip to the version matching our constraints
-    # if necessary, reinstall it to ensure that it's available on PATH as 'pip.exe'
-    call(
-        "python",
-        "-m",
-        "pip",
-        "install",
-        "--upgrade",
-        "pip",
-        *dependency_constraint_flags,
-        env=env,
-        cwd=venv_path,
-    )
-
    # update env with results from CIBW_ENVIRONMENT
    env = environment.as_dictionary(prev_environment=env)

@@ -296,23 +290,18 @@ def setup_python(
    call("python", "-c", "\"import struct; print(struct.calcsize('P') * 8)\"", env=env)
    where_python = call("where", "python", env=env, capture_stdout=True).splitlines()[0].strip()
    if where_python != str(venv_path / "Scripts" / "python.exe"):
-        print(
-            "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+        msg = "python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it."
+        raise errors.FatalError(msg)

    # check what pip version we're on
-    assert (venv_path / "Scripts" / "pip.exe").exists()
-    where_pip = call("where", "pip", env=env, capture_stdout=True).splitlines()[0].strip()
-    if where_pip.strip() != str(venv_path / "Scripts" / "pip.exe"):
-        print(
-            "cibuildwheel: pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it.",
-            file=sys.stderr,
-        )
-        sys.exit(1)
+    if not use_uv:
+        assert (venv_path / "Scripts" / "pip.exe").exists()
+        where_pip = call("where", "pip", env=env, capture_stdout=True).splitlines()[0].strip()
+        if where_pip.strip() != str(venv_path / "Scripts" / "pip.exe"):
+            msg = "pip available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert pip above it."
+            raise errors.FatalError(msg)

-    call("pip", "--version", env=env)
+        call("pip", "--version", env=env)

    log.step("Installing build tools...")
    if build_frontend == "build":
@@ -324,13 +313,24 @@ def setup_python(
            *dependency_constraint_flags,
            env=env,
        )
+    elif build_frontend == "build[uv]":
+        assert uv_path is not None
+        call(
+            uv_path,
+            "pip",
+            "install",
+            "--upgrade",
+            "build[virtualenv]",
+            *dependency_constraint_flags,
+            env=env,
+        )

    if python_libs_base:
        # Set up the environment for various backends to enable cross-compilation
        setup_setuptools_cross_compile(tmp, python_configuration, python_libs_base, env)
        setup_rust_cross_compile(tmp, python_configuration, python_libs_base, env)

-    return env
+    return base_python, env


 def build(options: Options, tmp_path: Path) -> None:
@@ -358,6 +358,9 @@ def build(options: Options, tmp_path: Path) -> None:
        for config in python_configurations:
            build_options = options.build_options(config.identifier)
            build_frontend = build_options.build_frontend or BuildFrontendConfig("pip")
+            use_uv = build_frontend.name == "build[uv]" and Version(config.version) >= Version(
+                "3.8"
+            )
            log.build_start(config.identifier)

            identifier_tmp_dir = tmp_path / config.identifier
@@ -373,13 +376,15 @@ def build(options: Options, tmp_path: Path) -> None:
                ]

            # install Python
-            env = setup_python(
+            base_python, env = setup_python(
                identifier_tmp_dir / "build",
                config,
                dependency_constraint_flags,
                build_options.environment,
                build_frontend.name,
            )
+            if not use_uv:
+                pip_version = get_pip_version(env)

            compatible_wheel = find_compatible_wheel(built_wheels, config.identifier)
            if compatible_wheel:
@@ -407,6 +412,16 @@ def build(options: Options, tmp_path: Path) -> None:
                )
                extra_flags += build_frontend.args

+                build_env = env.copy()
+                if not use_uv:
+                    build_env["VIRTUALENV_PIP"] = pip_version
+
+                if build_options.dependency_constraints:
+                    constraints_path = build_options.dependency_constraints.get_for_python_version(
+                        config.version
+                    )
+                    combine_constraints(build_env, constraints_path, identifier_tmp_dir)
+
                if build_frontend.name == "pip":
                    extra_flags += get_build_verbosity_extra_flags(build_options.build_verbosity)
                    # Path.resolve() is needed. Without it pip wheel may try to fetch package from pypi.org
@@ -420,46 +435,24 @@ def build(options: Options, tmp_path: Path) -> None:
                        f"--wheel-dir={built_wheel_dir}",
                        "--no-deps",
                        *extra_flags,
-                        env=env,
+                        env=build_env,
                    )
-                elif build_frontend.name == "build":
+                elif build_frontend.name == "build" or build_frontend.name == "build[uv]":
                    if not 0 <= build_options.build_verbosity < 2:
                        msg = f"build_verbosity {build_options.build_verbosity} is not supported for build frontend. Ignoring."
                        log.warning(msg)
-                    build_env = env.copy()
-                    if build_options.dependency_constraints:
-                        constraints_path = (
-                            build_options.dependency_constraints.get_for_python_version(
-                                config.version
-                            )
-                        )
-                        # Bug in pip <= 21.1.3 - we can't have a space in the
-                        # constraints file, and pip doesn't support drive letters
-                        # in uhi.  After probably pip 21.2, we can use uri. For
-                        # now, use a temporary file.
-                        if " " in str(constraints_path):
-                            assert " " not in str(identifier_tmp_dir)
-                            tmp_file = identifier_tmp_dir / "constraints.txt"
-                            tmp_file.write_bytes(constraints_path.read_bytes())
-                            constraints_path = tmp_file
-
-                        our_constraints = str(constraints_path)
-                        user_constraints = build_env.get("PIP_CONSTRAINT")
-                        build_env["PIP_CONSTRAINT"] = " ".join(
-                            c for c in [our_constraints, user_constraints] if c
-                        )
-
-                        build_env["VIRTUALENV_PIP"] = get_pip_version(env)
-                        call(
-                            "python",
-                            "-m",
-                            "build",
-                            build_options.package_dir,
-                            "--wheel",
-                            f"--outdir={built_wheel_dir}",
-                            *extra_flags,
-                            env=build_env,
-                        )
+                    if use_uv:
+                        extra_flags.append("--installer=uv")
+                    call(
+                        "python",
+                        "-m",
+                        "build",
+                        build_options.package_dir,
+                        "--wheel",
+                        f"--outdir={built_wheel_dir}",
+                        *extra_flags,
+                        env=build_env,
+                    )
                else:
                    assert_never(build_frontend)

@@ -503,12 +496,20 @@ def build(options: Options, tmp_path: Path) -> None:
                log.step("Testing wheel...")
                # set up a virtual environment to install and test from, to make sure
                # there are no dependencies that were pulled in at build time.
-                call("pip", "install", "virtualenv", *dependency_constraint_flags, env=env)
+                if not use_uv:
+                    call("pip", "install", "virtualenv", *dependency_constraint_flags, env=env)
+
                venv_dir = identifier_tmp_dir / "venv-test"

-                # Use --no-download to ensure determinism by using seed libraries
-                # built into virtualenv
-                call("python", "-m", "virtualenv", "--no-download", venv_dir, env=env)
+                if use_uv:
+                    call("uv", "venv", venv_dir, f"--python={base_python}", env=env)
+                else:
+                    # Use pip version from the initial env to ensure determinism
+                    venv_args = ["--no-periodic-update", f"--pip={pip_version}"]
+                    # In Python<3.12, setuptools & wheel are installed as well, use virtualenv embedded ones
+                    if Version(config.version) < Version("3.12"):
+                        venv_args.extend(("--setuptools=embed", "--wheel=embed"))
+                    call("python", "-m", "virtualenv", *venv_args, venv_dir, env=env)

                virtualenv_env = env.copy()
                virtualenv_env["PATH"] = os.pathsep.join(
@@ -517,6 +518,7 @@ def build(options: Options, tmp_path: Path) -> None:
                        virtualenv_env["PATH"],
                    ]
                )
+                virtualenv_env["VIRTUAL_ENV"] = str(venv_dir)

                # check that we are using the Python from the virtual environment
                call("where", "python", env=virtualenv_env)
@@ -529,9 +531,11 @@ def build(options: Options, tmp_path: Path) -> None:
                    )
                    shell(before_test_prepared, env=virtualenv_env)

+                pip = ["uv", "pip"] if use_uv else ["pip"]
+
                # install the wheel
                call(
-                    "pip",
+                    *pip,
                    "install",
                    str(repaired_wheel) + build_options.test_extras,
                    env=virtualenv_env,
@@ -539,7 +543,7 @@ def build(options: Options, tmp_path: Path) -> None:

                # test the wheel
                if build_options.test_requires:
-                    call("pip", "install", *build_options.test_requires, env=virtualenv_env)
+                    call(*pip, "install", *build_options.test_requires, env=virtualenv_env)

                # run the tests from a temp dir, with an absolute path in the command
                # (this ensures that Python runs the tests against the installed wheel
@@ -558,11 +562,13 @@ def build(options: Options, tmp_path: Path) -> None:

            # we're all done here; move it to output (remove if already exists)
            if compatible_wheel is None:
-                with suppress(FileNotFoundError):
-                    (build_options.output_dir / repaired_wheel.name).unlink()
-
-                shutil.move(str(repaired_wheel), build_options.output_dir)
-                built_wheels.append(build_options.output_dir / repaired_wheel.name)
+                output_wheel = build_options.output_dir.joinpath(repaired_wheel.name)
+                moved_wheel = move_file(repaired_wheel, output_wheel)
+                if moved_wheel != output_wheel.resolve():
+                    log.warning(
+                        "{repaired_wheel} was moved to {moved_wheel} instead of {output_wheel}"
+                    )
+                built_wheels.append(output_wheel)

            # clean up
            # (we ignore errors because occasionally Windows fails to unlink a file and we
@@ -571,7 +577,5 @@ def build(options: Options, tmp_path: Path) -> None:

            log.build_end()
    except subprocess.CalledProcessError as error:
-        log.step_end_with_error(
-            f"Command {error.cmd} failed with code {error.returncode}. {error.stdout}"
-        )
-        sys.exit(1)
+        msg = f"Command {error.cmd} failed with code {error.returncode}. {error.stdout or ''}"
+        raise errors.FatalError(msg) from error
@@ -4,19 +4,76 @@ title: Changelog

 # Changelog

+### v2.19.1
+
+- 🐛 Don't require setup-python on GHA for Pyodide (#1868)
+- 🐛 Specify full python path for uv (fixes issue in 0.2.10 & 0.2.11) (#1881)
+- 🛠 Update for pip 24.1b2 on CPython 3.13. (#1879)
+- 🛠 Fix a warning in our schema generation script. (#1866)
+- 🛠 Cleaner output on pytest 8-8.2. (#1865)
+
+
+### v2.19.0
+
+See the [release post](https://iscinumpy.dev/post/cibuildwheel-2-19-0/) for more info on new features!
+
+- 🌟 Add Pyodide platform. Set with `--platform pyodide` or `CIBW_PLATFORM: pyodide` on Linux with a host Python 3.12 to build WebAssembly wheels. Not accepted on PyPI currently, but usable directly in a website using Pyodide, for live docs, etc. (#1456, #1859)
+- 🌟 Add `build[uv]` backend, which will take a pre-existing uv install (or install `cibuildwheel[uv]`) and use `uv` for all environment setup and installs on Python 3.8+. This is significantly faster in most cases. (#1856)
+- ✨ Add free-threaded macOS builds and update CPython to 3.13.0b2. (#1854)
+- 🐛 Issue copying a wheel to a non-existent output dir fixed. (#1851, #1862)
+- 🐛 Better determinism for the test environment seeding. (#1835)
+- 🛠 `VIRTUAL_ENV` variable now set. (#1842)
+- 🛠 Remove a pip<21.3 workaround. (#1842)
+- 🛠 Error handling was refactored to use exceptions. (#1719)
+- 🛠 Hardcoded paths in tests avoided. (#1834)
+- 🛠 Single Python tests made more generic. (#1835)
+- 🛠 Sped up our ci by splitting up emulation tests. (#1839)
+
+
+
+### v2.18.1
+
+- 🌟 Add free-threaded Linux and Windows builds for 3.13. New identifiers `cp313t-*`, new option `CIBW_FREE_THREADED_SUPPORT`/`tool.cibuildwheel.free-threaded-support` required to opt-in. [See the docs](https://cibuildwheel.pypa.io/en/stable/options/#free-threaded-support) for more information. (#1831)
+- ✨ The `container-engine` is now a build (non-global) option. (#1792)
+- 🛠 The build backend for cibuildwheel is now hatchling. (#1297)
+- 🛠 Significant improvements and modernization to our noxfile. (#1823)
+- 🛠 Use pylint's new GitHub Actions reporter instead of a custom matcher. (#1823)
+- 🛠 Unpin virtualenv updates for Python 3.7+ (#1830)
+- 🐛 Fix running linux tests from Windows or macOS ARM. (#1788)
+- 📚 Fix our documentation build. (#1821)
+
+
+### v2.18.0
+
+_12 May 2024_
+
+- ✨ Adds CPython 3.13 support, under the prerelease flag [CIBW_PRERELEASE_PYTHONS](https://cibuildwheel.pypa.io/en/stable/options/#prerelease-pythons). This version of cibuildwheel uses 3.13.0b1. Free-threading mode is not available yet (#1657), waiting on official binaries (planned for beta 2) and pip support.
+
+    _While CPython is in beta, the ABI can change, so your wheels might not be compatible with the final release. For this reason, we don't recommend distributing wheels until RC1, at which point 3.13 will be available in cibuildwheel without the flag._ (#1815)
+
+- ✨ Musllinux now defaults to `musllinux_1_2`. You can set the older `musllinux_1_1` via config if needed. (#1817)
+- 🛠 No longer pre-seed setuptools/wheel in virtual environments (#1819)
+- 🛠 Respect the constraints file when building with pip, matching build (#1818)
+- 🛠 Use uv to compile our pinned dependencies, 10x faster and doesn't require special setup (#1778)
+- 🐛 Fix an issue with the schema (#1788)
+- 📚 Document the new delocate error checking macOS versions (#1766)
+- 📚 Document Rust builds (#1816)
+- 📚 Speed up our readthedocs builds with uv, 26 seconds -> 6 seconds to install dependencies (#1816)
+
+
 ### v2.17.0

 _11 March 2024_

 - 🌟 Adds the ability to inherit configuration in TOML overrides. This makes certain configurations much simpler. If you're overriding an option like `before-build` or `environment`, and you just want to add an  extra command or environment variable, you can just append (or prepend) to the previous config. See [the docs](https://cibuildwheel.pypa.io/en/stable/options/#inherit) for more information. (#1730)
- 🌟 Adds official support for native arm64 macOS GitHub runners. To use them, just specify `macos-14` as an `os` of your job in your workflow file. You can also keep `macos-13` in your build matrix to build x86_64. Check out the new [GitHub Actions example config](https://cibuildwheel.pypa.io/en/stable/setup/#github-actions).
- ✨ You no longer need to specify `--platform` to run cibuildwheel locally! Instead it will your platform automatically. This was a safety feature, no longer necessary. (#1727)
+- 🌟 Adds official support for native `arm64` macOS GitHub runners. To use them, just specify `macos-14` as an `os` of your job in your workflow file. You can also keep `macos-13` in your build matrix to build `x86_64`. Check out the new [GitHub Actions example config](https://cibuildwheel.pypa.io/en/stable/setup/#github-actions).
+- ✨ You no longer need to specify `--platform` to run cibuildwheel locally! Instead it will detect your platform automatically. This was a safety feature, no longer necessary. (#1727)
 - 🛠 Removed setuptools and wheel pinned versions. This only affects old-style projects without a `pyproject.toml`, projects with `pyproject.toml` are already getting fresh versions of their `build-system.requires` installed into an isolated environment. (#1725)
 - 🛠 Improve how the GitHub Action passes arguments (#1757)
 - 🛠 Remove a system-wide install of pipx in the GitHub Action (#1745)
- 🐛 No longer will cibuildwheel override the PIP_CONSTRAINT environment variable when using the `build` frontend. Instead it will be extended. (#1675)
- 🐛 Fix a bug where building and testing both x86_86 and arm64 wheels on the same runner caused the wrong architectures in the test environment (#1750)
- 🐛 Fix a bug that prevented testing a CPython 3.8 wheel targeting macOS 11+ on x86_64 (#1768)
+- 🐛 No longer will cibuildwheel override the `PIP_CONSTRAINT` environment variable when using the `build` frontend. Instead it will be extended. (#1675)
+- 🐛 Fix a bug where building and testing both `x86_86` and `arm64` wheels on the same runner caused the wrong architectures in the test environment (#1750)
+- 🐛 Fix a bug that prevented testing a CPython 3.8 wheel targeting macOS 11+ on `x86_64` (#1768)
 - 📚 Moved the docs onto the official PyPA domain - they're now available at https://cibuildwheel.pypa.io . (#1775)
 - 📚 Docs and examples improvements (#1762, #1734)

@@ -93,7 +150,7 @@ _10 July 2023_
 - 🛠 Updates the prerelease CPython 3.12 version to 3.12.0b3.
 - ✨ Allow the use of the `{wheel}` placeholder in CIBW_TEST_COMMAND (#1533)
 - 📚 Docs & examples updates (#1532, #1416)
- ⚠️ Removed support for running cibuildwheel in Python 3.7. Python 3.7 is EOL. However, cibuildwheel continues to build Python 3.7 wheels for the moment. (#1175)
+- ⚠️  Removed support for running cibuildwheel in Python 3.7. Python 3.7 is EOL. However, cibuildwheel continues to build Python 3.7 wheels for the moment. (#1175)

 ### v2.13.1

@@ -177,7 +177,7 @@ Then, increment the project version number using:
 bin/bump_version.py
 ```

-You'll be prompted to enter the new version number. Update the changelog when prompted. The script will create a 'bump version' commit and version tag.
+(or `nox -s bump_version`) You'll be prompted to enter the new version number. Update the changelog when prompted. The script will create a 'bump version' commit and version tag.

 Finally, cut the release and push to GitHub.

@@ -186,3 +186,5 @@ git push && git push --tags
 ```

 Then head to https://github.com/pypa/cibuildwheel/releases and create a GitHub release from the new tag, pasting in the changelog entry. Once the release is created inside GitHub, a CI job will create the assets and upload them to PyPI.
+
+If there were any schema updates, run `pipx run ./bin/generate_schema.py --schemastore > partial-cibuildwheel.json` and contribute the changes to SchemaStore.
@@ -26,7 +26,7 @@
  notes: A simple C extension, without external dependencies

 - name: websockets
-  gh: aaugustin/websockets
+  gh: python-websockets/websockets
  ci: [travisci]
  ci_config: .travis.yml
  os: [apple, linux]
@@ -325,12 +325,12 @@
  notes: Full range of wheels for setuptools rust, with auto release and PyPI deploy.

 - name: python-snappy
-  gh: andrix/python-snappy
+  gh: intake/python-snappy
  ci: [github]
  os: [apple, linux, windows]

 - name: sourmash
-  gh: dib-lab/sourmash
+  gh: sourmash-bio/sourmash
  ci: [github]
  os: [apple, linux, windows]

@@ -418,7 +418,7 @@
  notes: Tornado is a Python web framework and asynchronous networking library. Uses stable ABI for a small C extension.

 - name: pytorch-fairseq
-  gh: pytorch/fairseq
+  gh: facebookresearch/fairseq
  ci: [github]
  os: [apple, linux]

@@ -475,7 +475,7 @@
  os: [apple, linux, windows]

 - name: OpenSpiel
-  gh: deepmind/open_spiel
+  gh: google-deepmind/open_spiel
  ci: [github]
  os: [apple, linux]

@@ -505,7 +505,7 @@
  os: [apple, linux, windows]

 - name: OpenTimelineIO
-  gh: PixarAnimationStudios/OpenTimelineIO
+  gh: AcademySoftwareFoundation/OpenTimelineIO
  ci: [github]
  os: [apple, linux, windows]

@@ -584,7 +584,7 @@
  notes: Includes GPU support for linux wheels

 - name: power-grid-model
-  gh: alliander-opensource/power-grid-model
+  gh: PowerGridModel/power-grid-model
  ci: [github]
  os: [windows, apple, linux]
  notes: Python/C++ library for distribution power system analysis
@@ -10,7 +10,7 @@ title: Tips and tricks

 Linux wheels are built in [`manylinux`/`musllinux` containers](https://github.com/pypa/manylinux) to provide binary compatible wheels on Linux, according to [PEP 600](https://www.python.org/dev/peps/pep-0600/) / [PEP 656](https://www.python.org/dev/peps/pep-0656/). Because of this, when building with `cibuildwheel` on Linux, a few things should be taken into account:

-   Programs and libraries are not installed on the CI runner host, but rather should be installed inside the container - using `yum` for `manylinux2010` or `manylinux2014`, `apt-get` for `manylinux_2_24` and `apk` for `musllinux_1_1`, or manually. The same goes for environment variables that are potentially needed to customize the wheel building.
+-   Programs and libraries are not installed on the CI runner host, but rather should be installed inside the container - using `yum` for `manylinux2010` or `manylinux2014`, `apt-get` for `manylinux_2_24`, `dnf` for `manylinux_2_28` and `apk` for `musllinux_1_1` or `musllinux_1_2`, or manually. The same goes for environment variables that are potentially needed to customize the wheel building.

    `cibuildwheel` supports this by providing the [`CIBW_ENVIRONMENT`](options.md#environment) and [`CIBW_BEFORE_ALL`](options.md#before-all) options to setup the build environment inside the running container.

@@ -142,7 +142,7 @@ There are two suggested methods for keeping cibuildwheel up to date that instead
 If you use GitHub Actions for builds, you can use cibuildwheel as an action:

 ```yaml
-uses: pypa/cibuildwheel@v2.17.0
+uses: pypa/cibuildwheel@v2.19.1
 ```

 This is a composite step that just runs cibuildwheel using pipx. You can set command-line options as `with:` parameters, and use `env:` as normal.
@@ -164,7 +164,7 @@ The second option, and the only one that supports other CI systems, is using a `

 ```bash
 # requirements-cibw.txt
-cibuildwheel==2.17.0
+cibuildwheel==2.19.1
 ```

 Then your install step would have `python -m pip install -r requirements-cibw.txt` in it. Your `.github/dependabot.yml` file could look like this:
@@ -282,6 +282,27 @@ For these reasons, it's strongly recommended to not use brew for native library
 [Homebrew]: https://brew.sh/
 [delocate]: https://github.com/matthew-brett/delocate

+### Building Rust wheels
+
+If you build Rust wheels, you need to download the Rust compilers in manylinux.
+If you support 32-bit Windows, you need to add this as a potential target. You
+can do this on GitHub Actions, for example, with:
+
+```yaml
+CIBW_BEFORE_ALL_LINUX: curl -sSf https://sh.rustup.rs | sh -s -- -y
+CIBW_BEFORE_ALL_WINDOWS: rustup target add i686-pc-windows-msvc
+CIBW_ENVIRONMENT_LINUX: "PATH=$HOME/.cargo/bin:$PATH"
+```
+
+Rust does not provide Cargo for musllinux 32-bit, so that needs to be skipped:
+
+```toml
+[tool.cibuildwheel]
+skip = ["*-musllinux_i686"]
+```
+
+Also see [maturin-action](https://github.com/PyO3/maturin-action) which is optimized for Rust wheels, builds the non-Python Rust modules once, and can cross-compile (and can build 32-bit musl, for example).
+
 ### macOS: ModuleNotFoundError

 Calling cibuildwheel from a python3 script and getting a `ModuleNotFoundError`? Due to a (fixed) [bug](https://bugs.python.org/issue22490) in CPython, you'll need to [unset the `__PYVENV_LAUNCHER__` variable](https://github.com/pypa/cibuildwheel/issues/133#issuecomment-478288597) before activating a venv.
@@ -307,7 +328,7 @@ Solutions to this vary, but the simplest is to use pipx:
 # most runners have pipx preinstalled, but in case you don't
 python3 -m pip install pipx

-pipx run cibuildwheel==2.17.0 --output-dir wheelhouse
+pipx run cibuildwheel==2.19.1 --output-dir wheelhouse
 pipx run twine upload wheelhouse/*.whl
 ```

@@ -355,6 +376,13 @@ sh "/Applications/Python 3.8/Install Certificates.command"

 Then cibuildwheel will detect that it's installed and use it instead. However, you probably don't want to build x86_64 wheels on this Python, unless you're happy with them only supporting macOS 11+.

+### macOS: Library dependencies do not satisfy target MacOS
+
+Since delocate 0.11.0 there is added verification that the library binary dependencies match the target macOS version. This is to prevent the situation where a wheel platform tag is lower than the actual minimum macOS version required by the library. To resolve this error you need to build the library to the same macOS version as the target wheel (for example using `MACOSX_DEPLOYMENT_TARGET` environment variable).
+Alternatively, you could set `MACOSX_DEPLOYMENT_TARGET` in `CIBW_ENVIRONMENT` to correctly label the wheel as incompatible with older macOS versions.
+
+This error may happen when you install a library using a package manager like Homebrew, which compiles the library for the macOS version of the build machine. This is not suitable for wheels, as the library will only work on the same macOS version as the build machine. You should compile the library yourself, or use a precompiled binary that matches the target macOS version.
+
 ### Windows: 'ImportError: DLL load failed: The specific module could not be found'

 Visual Studio and MSVC link the compiled binary wheels to the Microsoft Visual C++ Runtime. Normally, the C parts of the runtime are included with Python, but the C++ components are not. When compiling modules using C++, it is possible users will run into problems on systems that do not have the full set of runtime libraries installed. The solution is to ask users to download the corresponding Visual C++ Redistributable from the [Microsoft website](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads) and install it.
@@ -1,10 +1,10 @@
 from __future__ import annotations

+import os
 import subprocess
+import sysconfig
 from typing import Any

-# Requires Python 3.7+
-

 def define_env(env: Any) -> None:
    "Hook function for mkdocs-macros"
@@ -12,4 +12,7 @@ def define_env(env: Any) -> None:
    @env.macro
    def subprocess_run(*args: str) -> str:
        "Run a subprocess and return the stdout"
-        return subprocess.run(args, check=True, capture_output=True, text=True).stdout
+        env = os.environ.copy()
+        scripts = sysconfig.get_path("scripts")
+        env["PATH"] = f"{scripts}{os.pathsep}{env.get('PATH', '')}"
+        return subprocess.run(args, check=True, capture_output=True, text=True, env=env).stdout
@@ -91,9 +91,9 @@ You can configure cibuildwheel with a config file, such as `pyproject.toml`.
 Options have the same names as the environment variable overrides, but are
 placed in `[tool.cibuildwheel]` and are lower case, with dashes, following
 common [TOML][] practice. Anything placed in subsections `linux`, `windows`,
-or `macos` will only affect those platforms. Lists can be used instead of
-strings for items that are naturally a list. Multiline strings also work just
-like in the environment variables. Environment variables will take
+`macos`, or `pyodide` will only affect those platforms. Lists can be used
+instead of strings for items that are naturally a list. Multiline strings also
+work just like in the environment variables. Environment variables will take
 precedence if defined.

 The example above using environment variables could have been written like this:
@@ -247,7 +247,7 @@ environment variables will completely override any TOML configuration.

 > Override the auto-detected target platform

-Options: `auto` `linux` `macos` `windows`
+Options: `auto` `linux` `macos` `windows` `pyodide`

 Default: `auto`

@@ -255,6 +255,7 @@ Default: `auto`

 - For `linux`, you need [Docker or Podman](#container-engine) running, on Linux, macOS, or Windows.
 - For `macos` and `windows`, you need to be running on the respective system, with a working compiler toolchain installed - Xcode Command Line tools for macOS, and MSVC for Windows.
+- For `pyodide` you need to be on an x86-64 linux runner and `python3.12` must be available in `PATH`.

 This option can also be set using the [command-line option](#command-line) `--platform`. This option is not available in the `pyproject.toml` config.

@@ -296,6 +297,7 @@ When setting the options, you can use shell-style globbing syntax, as per [fnmat
 | Python 3.10   | cp310-macosx_x86_64<br/>cp310-macosx_universal2<br/>cp310-macosx_arm64 | cp310-win_amd64<br/>cp310-win32<br/>cp310-win_arm64 | cp310-manylinux_x86_64<br/>cp310-manylinux_i686<br/>cp310-musllinux_x86_64<br/>cp310-musllinux_i686 | cp310-manylinux_aarch64<br/>cp310-manylinux_ppc64le<br/>cp310-manylinux_s390x<br/>cp310-musllinux_aarch64<br/>cp310-musllinux_ppc64le<br/>cp310-musllinux_s390x |
 | Python 3.11   | cp311-macosx_x86_64<br/>cp311-macosx_universal2<br/>cp311-macosx_arm64 | cp311-win_amd64<br/>cp311-win32<br/>cp311-win_arm64 | cp311-manylinux_x86_64<br/>cp311-manylinux_i686<br/>cp311-musllinux_x86_64<br/>cp311-musllinux_i686 | cp311-manylinux_aarch64<br/>cp311-manylinux_ppc64le<br/>cp311-manylinux_s390x<br/>cp311-musllinux_aarch64<br/>cp311-musllinux_ppc64le<br/>cp311-musllinux_s390x |
 | Python 3.12   | cp312-macosx_x86_64<br/>cp312-macosx_universal2<br/>cp312-macosx_arm64 | cp312-win_amd64<br/>cp312-win32<br/>cp312-win_arm64 | cp312-manylinux_x86_64<br/>cp312-manylinux_i686<br/>cp312-musllinux_x86_64<br/>cp312-musllinux_i686 | cp312-manylinux_aarch64<br/>cp312-manylinux_ppc64le<br/>cp312-manylinux_s390x<br/>cp312-musllinux_aarch64<br/>cp312-musllinux_ppc64le<br/>cp312-musllinux_s390x |
+| Python 3.13   | cp313-macosx_x86_64<br/>cp313-macosx_universal2<br/>cp313-macosx_arm64 | cp313-win_amd64<br/>cp313-win32<br/>cp313-win_arm64 | cp313-manylinux_x86_64<br/>cp313-manylinux_i686<br/>cp313-musllinux_x86_64<br/>cp313-musllinux_i686 | cp313-manylinux_aarch64<br/>cp313-manylinux_ppc64le<br/>cp313-manylinux_s390x<br/>cp313-musllinux_aarch64<br/>cp313-musllinux_ppc64le<br/>cp313-musllinux_s390x |
 | PyPy3.7 v7.3  | pp37-macosx_x86_64                                                     | pp37-win_amd64                                      | pp37-manylinux_x86_64<br/>pp37-manylinux_i686                                                       | pp37-manylinux_aarch64                                                                                                                                          |
 | PyPy3.8 v7.3  | pp38-macosx_x86_64<br/>pp38-macosx_arm64                               | pp38-win_amd64                                      | pp38-manylinux_x86_64<br/>pp38-manylinux_i686                                                       | pp38-manylinux_aarch64                                                                                                                                          |
 | PyPy3.9 v7.3  | pp39-macosx_x86_64<br/>pp39-macosx_arm64                               | pp39-win_amd64                                      | pp39-manylinux_x86_64<br/>pp39-manylinux_i686                                                       | pp39-manylinux_aarch64                                                                                                                                          |
@@ -308,6 +310,9 @@ For CPython, the minimally supported macOS version is 10.9; for PyPy 3.7, macOS

 Windows arm64 platform support is experimental.

+For an experimental WebAssembly build with `--platform pyodide`,
+`cp312-pyodide_wasm32` is the only platform identifier.
+
 See the [cibuildwheel 1 documentation](https://cibuildwheel.pypa.io/en/1.x/) for past end-of-life versions of Python, and PyPy2.7.

 #### Examples
@@ -407,6 +412,53 @@ See the [cibuildwheel 1 documentation](https://cibuildwheel.pypa.io/en/1.x/) for
  }
 </style>

+### `CIBW_FREE_THREADED_SUPPORT` {: #free-threaded-support}
+
+> Choose whether free-threaded variants should be built
+
+[PEP 703](https://www.python.org/dev/peps/pep-0703) introduced variants of CPython that can be built without the Global Interpreter Lock (GIL).
+Those variants are also known as free-threaded / no-gil.
+
+Building for free-threaded variants is disabled by default.
+
+Building can be enabled by setting this option to `true`. The free-threaded compatible wheels will be built in addition to the standard wheels.
+
+This option doesn't support overrides.
+If you need to enable/disable it per platform or python version, set this option to `true` and use [`CIBW_BUILD`](#build-skip)/[`CIBW_SKIP`](#build-skip) options to filter the builds.
+
+The build identifiers for those variants have a `t` suffix in their `python_tag` (e.g. `cp313t-manylinux_x86_64`)
+
+!!! note
+    This feature is experimental: [What’s New In Python 3.13](https://docs.python.org/3.13/whatsnew/3.13.html#free-threaded-cpython)
+
+#### Examples
+
+!!! tab examples "Environment variables"
+
+    ```yaml
+    # Enable free-threaded support
+    CIBW_FREE_THREADED_SUPPORT: 1
+
+    # Skip building free-threaded compatible wheels on Windows
+    CIBW_FREE_THREADED_SUPPORT: 1
+    CIBW_SKIP: *t-win*
+    ```
+
+    It is generally recommended to use `free-threaded-support` in a config file as you can statically declare that you
+    support free-threaded builds.
+
+!!! tab examples "pyproject.toml"
+
+    ```toml
+    [tool.cibuildwheel]
+    # Enable free-threaded support
+    free-threaded-support = true
+
+    # Skip building free-threaded compatible wheels on Windows
+    free-threaded-support = true
+    skip = "*t-win*"
+    ```
+
 ### `CIBW_ARCHS` {: #archs}
 > Change the architectures built on your machine by default.

@@ -426,6 +478,7 @@ Options:
 - Linux: `x86_64` `i686` `aarch64` `ppc64le` `s390x`
 - macOS: `x86_64` `arm64` `universal2`
 - Windows: `AMD64` `x86` `ARM64`
+- Pyodide: `wasm32`
 - `auto`: The default archs for your machine - see the table below.
    - `auto64`: Just the 64-bit auto archs
    - `auto32`: Just the 32-bit auto archs
@@ -571,7 +624,7 @@ This option can also be set using the [command-line option](#command-line) `--pr
 ## Build customization

 ### `CIBW_BUILD_FRONTEND` {: #build-frontend}
-> Set the tool to use to build, either "pip" (default for now) or "build"
+> Set the tool to use to build, either "pip" (default for now), "build", or "build[uv]"

 Options:

@@ -583,17 +636,30 @@ Default: `pip`
 Choose which build frontend to use. Can either be "pip", which will run
 `python -m pip wheel`, or "build", which will run `python -m build --wheel`.

+You can also use "build[uv]", which will use an external [uv][] everywhere
+possible, both through `--installer=uv` passed to build, as well as when making
+all build and test environments. This will generally speed up cibuildwheel.
+Make sure you have an external uv on Windows and macOS, either by
+pre-installing it, or installing cibuildwheel with the uv extra,
+`cibuildwheel[uv]`. `uv` will not be used for Python 3.6 or Python 3.7. You
+cannot use uv currently on Windows for ARM or for musllinux on s390x as
+binaries are not provided by uv. Legacy dependencies like setuptools on Python
+< 3.12 and pip are not installed if using uv.
+
+Pyodide ignores this setting, as only "build" is supported.
+
 You can specify extra arguments to pass to `pip wheel` or `build` using the
 optional `args` option.

 !!! tip
-    Until v2.0.0, [pip] was the only way to build wheels, and is still the
+    Until v2.0.0, [pip][] was the only way to build wheels, and is still the
    default. However, we expect that at some point in the future, cibuildwheel
-    will change the default to [build], in line with the PyPA's recommendation.
+    will change the default to [build][], in line with the PyPA's recommendation.
    If you want to try `build` before this, you can use this option.

 [pip]: https://pip.pypa.io/en/stable/cli/pip_wheel/
 [build]: https://github.com/pypa/build/
+[uv]: https://github.com/astral-sh/uv

 #### Examples

@@ -608,6 +674,12 @@ optional `args` option.

    # supply an extra argument to 'pip wheel'
    CIBW_BUILD_FRONTEND: "pip; args: --no-build-isolation"
+
+    # Use uv and build
+    CIBW_BUILD_FRONTEND: "build[uv]"
+
+    # Use uv and build with an argument
+    CIBW_BUILD_FRONTEND: "build[uv]; args: --no-isolation"
    ```

 !!! tab examples "pyproject.toml"
@@ -622,6 +694,12 @@ optional `args` option.

    # supply an extra argument to 'pip wheel'
    build-frontend = { name = "pip", args = ["--no-build-isolation"] }
+
+    # Use uv and build
+    build-frontend = "build[uv]"
+
+    # Use uv and build with an argument
+    build-frontend = { name = "build[uv]", args = ["--no-isolation"] }
    ```

 ### `CIBW_CONFIG_SETTINGS` {: #config-settings}
@@ -636,7 +714,7 @@ a table of items, including arrays.
    single values.

 Platform-specific environment variables also available:<br/>
-`CIBW_CONFIG_SETTINGS_MACOS` | `CIBW_CONFIG_SETTINGS_WINDOWS` | `CIBW_CONFIG_SETTINGS_LINUX`
+`CIBW_CONFIG_SETTINGS_MACOS` | `CIBW_CONFIG_SETTINGS_WINDOWS` | `CIBW_CONFIG_SETTINGS_LINUX` | `CIBW_CONFIG_SETTINGS_PYODIDE`


 #### Examples
@@ -667,7 +745,7 @@ You can use `$PATH` syntax to insert other variables, or the `$(pwd)` syntax to
 To specify more than one environment variable, separate the assignments by spaces.

 Platform-specific environment variables are also available:<br/>
-`CIBW_ENVIRONMENT_MACOS` | `CIBW_ENVIRONMENT_WINDOWS` | `CIBW_ENVIRONMENT_LINUX`
+`CIBW_ENVIRONMENT_MACOS` | `CIBW_ENVIRONMENT_WINDOWS` | `CIBW_ENVIRONMENT_LINUX` | `CIBW_ENVIRONMENT_PYODIDE`

 #### Examples

@@ -740,7 +818,7 @@ Platform-specific environment variables are also available:<br/>
    In configuration mode, you can use a [TOML][] table instead of a raw string as shown above.

 !!! note
-    cibuildwheel always defines the environment variable `CIBUILDWHEEL=1`. This can be useful for [building wheels with optional extensions](faq.md#building-packages-with-optional-c-extensions).
+    cibuildwheel always defines the environment variable `CIBUILDWHEEL=1`. This can be useful for [building wheels with optional extensions](faq.md#optional-extensions).

 !!! note
    To do its work, cibuildwheel sets the variables `VIRTUALENV_PIP`, `DIST_EXTRA_CONFIG`, `SETUPTOOLS_EXT_SUFFIX`, `PIP_DISABLE_PIP_VERSION_CHECK`, `PIP_ROOT_USER_ACTION`, and it extends the variables `PATH` and `PIP_CONSTRAINT`. Your assignments to these options might be replaced or extended.
@@ -799,7 +877,7 @@ On linux, overriding it triggers a new container launch. It cannot be overridden
 on macOS and Windows.

 Platform-specific environment variables also available:<br/>
-`CIBW_BEFORE_ALL_MACOS` | `CIBW_BEFORE_ALL_WINDOWS` | `CIBW_BEFORE_ALL_LINUX`
+`CIBW_BEFORE_ALL_MACOS` | `CIBW_BEFORE_ALL_WINDOWS` | `CIBW_BEFORE_ALL_LINUX` | `CIBW_BEFORE_ALL_PYODIDE`

 !!! note

@@ -864,7 +942,7 @@ The active Python binary can be accessed using `python`, and pip with `pip`; cib
 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

 Platform-specific environment variables are also available:<br/>
- `CIBW_BEFORE_BUILD_MACOS` | `CIBW_BEFORE_BUILD_WINDOWS` | `CIBW_BEFORE_BUILD_LINUX`
+ `CIBW_BEFORE_BUILD_MACOS` | `CIBW_BEFORE_BUILD_WINDOWS` | `CIBW_BEFORE_BUILD_LINUX` | `CIBW_BEFORE_BUILD_PYODIDE`

 #### Examples

@@ -945,6 +1023,7 @@ Default:
 - on Linux: `'auditwheel repair -w {dest_dir} {wheel}'`
 - on macOS: `'delocate-wheel --require-archs {delocate_archs} -w {dest_dir} -v {wheel}'`
 - on Windows: `''`
+- on Pyodide: `''`

 A shell command to repair a built wheel by copying external library dependencies into the wheel tree and relinking them.
 The command is run on each built wheel (except for pure Python ones) before testing it.
@@ -958,7 +1037,7 @@ The following placeholders must be used inside the command and will be replaced
 The command is run in a shell, so you can run multiple commands like `cmd1 && cmd2`.

 Platform-specific environment variables are also available:<br/>
-`CIBW_REPAIR_WHEEL_COMMAND_MACOS` | `CIBW_REPAIR_WHEEL_COMMAND_WINDOWS` | `CIBW_REPAIR_WHEEL_COMMAND_LINUX`
+`CIBW_REPAIR_WHEEL_COMMAND_MACOS` | `CIBW_REPAIR_WHEEL_COMMAND_WINDOWS` | `CIBW_REPAIR_WHEEL_COMMAND_LINUX` | `CIBW_REPAIR_WHEEL_COMMAND_PYODIDE`

 !!! tip
    cibuildwheel doesn't yet ship a default repair command for Windows.
@@ -969,6 +1048,12 @@ Platform-specific environment variables are also available:<br/>

    [Delvewheel]: https://github.com/adang1345/delvewheel

+!!! tip
+    When using `--platform pyodide`, `pyodide build` is used to do the build,
+    which already uses `auditwheel-emscripten` to repair the wheel, so the default
+    repair command is empty. If there is a way to do this in two steps in the future,
+    this could change.
+
 #### Examples

 !!! tab examples "Environment variables"
@@ -1056,11 +1141,11 @@ The available options are (default value):
 - `CIBW_MANYLINUX_S390X_IMAGE` ([`quay.io/pypa/manylinux2014_s390x`](https://quay.io/pypa/manylinux2014_s390x))
 - `CIBW_MANYLINUX_PYPY_AARCH64_IMAGE` ([`quay.io/pypa/manylinux2014_aarch64`](https://quay.io/pypa/manylinux2014_aarch64))
 - `CIBW_MANYLINUX_PYPY_I686_IMAGE` ([`quay.io/pypa/manylinux2014_i686`](https://quay.io/pypa/manylinux2014_i686))
- `CIBW_MUSLLINUX_X86_64_IMAGE` ([`quay.io/pypa/musllinux_1_1_x86_64`](https://quay.io/pypa/musllinux_1_1_x86_64))
- `CIBW_MUSLLINUX_I686_IMAGE` ([`quay.io/pypa/musllinux_1_1_i686`](https://quay.io/pypa/musllinux_1_1_i686))
- `CIBW_MUSLLINUX_AARCH64_IMAGE` ([`quay.io/pypa/musllinux_1_1_aarch64`](https://quay.io/pypa/musllinux_1_1_aarch64))
- `CIBW_MUSLLINUX_PPC64LE_IMAGE` ([`quay.io/pypa/musllinux_1_1_ppc64le`](https://quay.io/pypa/musllinux_1_1_ppc64le))
- `CIBW_MUSLLINUX_S390X_IMAGE` ([`quay.io/pypa/musllinux_1_1_s390x`](https://quay.io/pypa/musllinux_1_1_s390x))
+- `CIBW_MUSLLINUX_X86_64_IMAGE` ([`quay.io/pypa/musllinux_1_2_x86_64`](https://quay.io/pypa/musllinux_1_2_x86_64))
+- `CIBW_MUSLLINUX_I686_IMAGE` ([`quay.io/pypa/musllinux_1_2_i686`](https://quay.io/pypa/musllinux_1_2_i686))
+- `CIBW_MUSLLINUX_AARCH64_IMAGE` ([`quay.io/pypa/musllinux_1_2_aarch64`](https://quay.io/pypa/musllinux_1_2_aarch64))
+- `CIBW_MUSLLINUX_PPC64LE_IMAGE` ([`quay.io/pypa/musllinux_1_2_ppc64le`](https://quay.io/pypa/musllinux_1_2_ppc64le))
+- `CIBW_MUSLLINUX_S390X_IMAGE` ([`quay.io/pypa/musllinux_1_2_s390x`](https://quay.io/pypa/musllinux_1_2_s390x))

 Set an alternative Docker image to be used for building [manylinux / musllinux](https://github.com/pypa/manylinux) wheels.

@@ -1071,7 +1156,7 @@ For `CIBW_MUSLLINUX_*_IMAGE`, the value of this option can either be set to `mus

 If this option is blank, it will fall though to the next available definition (environment variable -> pyproject.toml -> default).

-If setting a custom image, you'll need to make sure it can be used in the same way as the default images: all necessary Python and pip versions need to be present in `/opt/python/`, and the auditwheel tool needs to be present for cibuildwheel to work. Apart from that, the architecture and relevant shared system libraries need to be compatible to the relevant standard to produce valid manylinux1/manylinux2010/manylinux2014/manylinux_2_24/manylinux_2_28/musllinux_1_1 wheels (see [pypa/manylinux on GitHub](https://github.com/pypa/manylinux), [PEP 513](https://www.python.org/dev/peps/pep-0513/), [PEP 571](https://www.python.org/dev/peps/pep-0571/), [PEP 599](https://www.python.org/dev/peps/pep-0599/), [PEP 600](https://www.python.org/dev/peps/pep-0600/) and [PEP 656](https://www.python.org/dev/peps/pep-0656/) for more details).
+If setting a custom image, you'll need to make sure it can be used in the same way as the default images: all necessary Python and pip versions need to be present in `/opt/python/`, and the auditwheel tool needs to be present for cibuildwheel to work. Apart from that, the architecture and relevant shared system libraries need to be compatible to the relevant standard to produce valid manylinux1/manylinux2010/manylinux2014/manylinux_2_24/manylinux_2_28/musllinux_1_1/musllinux_1_2 wheels (see [pypa/manylinux on GitHub](https://github.com/pypa/manylinux), [PEP 513](https://www.python.org/dev/peps/pep-0513/), [PEP 571](https://www.python.org/dev/peps/pep-0571/), [PEP 599](https://www.python.org/dev/peps/pep-0599/), [PEP 600](https://www.python.org/dev/peps/pep-0600/) and [PEP 656](https://www.python.org/dev/peps/pep-0656/) for more details).

 Auditwheel detects the version of the manylinux / musllinux standard in the image through the `AUDITWHEEL_PLAT` environment variable, as cibuildwheel has no way of detecting the correct `--plat` command line argument to pass to auditwheel for a custom image. If a custom image does not correctly set this `AUDITWHEEL_PLAT` environment variable, the `CIBW_ENVIRONMENT` option can be used to do so (e.g., `CIBW_ENVIRONMENT='AUDITWHEEL_PLAT="manylinux2010_$(uname -m)"'`).

@@ -1102,6 +1187,10 @@ Auditwheel detects the version of the manylinux / musllinux standard in the imag
    # Build using a different image from the docker registry
    CIBW_MANYLINUX_X86_64_IMAGE: dockcross/manylinux-x64
    CIBW_MANYLINUX_I686_IMAGE: dockcross/manylinux-x86
+
+    # Build musllinux wheels using the musllinux_1_1 image
+    CIBW_MUSLLINUX_X86_64_IMAGE: musllinux_1_1
+    CIBW_MUSLLINUX_I686_IMAGE: musllinux_1_1
    ```

 !!! tab examples "pyproject.toml"
@@ -1129,6 +1218,10 @@ Auditwheel detects the version of the manylinux / musllinux standard in the imag
    # Build using a different image from the docker registry
    manylinux-x86_64-image = "dockcross/manylinux-x64"
    manylinux-i686-image = "dockcross/manylinux-x86"
+
+    # Build musllinux wheels using the musllinux_1_1 image
+    musllinux-x86_64-image = "musllinux_1_1"
+    musllinux-i686-image = "musllinux_1_1"
    ```

    Like any other option, these can be placed in `[tool.cibuildwheel.linux]`
@@ -1225,7 +1318,7 @@ here and it will be used instead.
    `./constraints.txt` if that's not found.

 Platform-specific environment variables are also available:<br/>
-`CIBW_DEPENDENCY_VERSIONS_MACOS` | `CIBW_DEPENDENCY_VERSIONS_WINDOWS`
+`CIBW_DEPENDENCY_VERSIONS_MACOS` | `CIBW_DEPENDENCY_VERSIONS_WINDOWS` | `CIBW_DEPENDENCY_VERSIONS_PYODIDE`

 !!! note
    This option does not affect the tools used on the Linux build - those versions
@@ -1283,7 +1376,7 @@ not be installed after building.
 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

 Platform-specific environment variables are also available:<br/>
-`CIBW_TEST_COMMAND_MACOS` | `CIBW_TEST_COMMAND_WINDOWS` | `CIBW_TEST_COMMAND_LINUX`
+`CIBW_TEST_COMMAND_MACOS` | `CIBW_TEST_COMMAND_WINDOWS` | `CIBW_TEST_COMMAND_LINUX` | `CIBW_TEST_COMMAND_PYODIDE`

 #### Examples

@@ -1346,7 +1439,7 @@ The active Python binary can be accessed using `python`, and pip with `pip`; cib
 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

 Platform-specific environment variables are also available:<br/>
- `CIBW_BEFORE_TEST_MACOS` | `CIBW_BEFORE_TEST_WINDOWS` | `CIBW_BEFORE_TEST_LINUX`
+ `CIBW_BEFORE_TEST_MACOS` | `CIBW_BEFORE_TEST_WINDOWS` | `CIBW_BEFORE_TEST_LINUX` | `CIBW_BEFORE_TEST_PYODIDE`

 #### Examples

@@ -1406,7 +1499,7 @@ Platform-specific environment variables are also available:<br/>
 Space-separated list of dependencies required for running the tests.

 Platform-specific environment variables are also available:<br/>
-`CIBW_TEST_REQUIRES_MACOS` | `CIBW_TEST_REQUIRES_WINDOWS` | `CIBW_TEST_REQUIRES_LINUX`
+`CIBW_TEST_REQUIRES_MACOS` | `CIBW_TEST_REQUIRES_WINDOWS` | `CIBW_TEST_REQUIRES_LINUX` | `CIBW_TEST_REQUIRES_PYODIDE`

 #### Examples

@@ -1446,7 +1539,7 @@ tests. This can be used to avoid having to redefine test dependencies in
 `setup.cfg` or `setup.py`.

 Platform-specific environment variables are also available:<br/>
-`CIBW_TEST_EXTRAS_MACOS` | `CIBW_TEST_EXTRAS_WINDOWS` | `CIBW_TEST_EXTRAS_LINUX`
+`CIBW_TEST_EXTRAS_MACOS` | `CIBW_TEST_EXTRAS_WINDOWS` | `CIBW_TEST_EXTRAS_LINUX` | `CIBW_TEST_EXTRAS_PYODIDE`

 #### Examples

@@ -1519,13 +1612,27 @@ Default: Off (0).
 export CIBW_DEBUG_KEEP_CONTAINER=TRUE
 ```

+### `CIBW_DEBUG_TRACEBACK`
+> Print full traceback when errors occur.
+
+Print a full traceback for the cibuildwheel process when errors occur. This
+option is provided for debugging cibuildwheel.
+
+This option can also be set using the [command-line option](#command-line) `--debug-traceback`.
+
+#### Examples
+
+```shell
+export CIBW_DEBUG_TRACEBACK=TRUE
+```
+
 ### `CIBW_BUILD_VERBOSITY` {: #build-verbosity}
 > Increase/decrease the output of pip wheel

 A number from 1 to 3 to increase the level of verbosity (corresponding to invoking pip with `-v`, `-vv`, and `-vvv`), between -1 and -3 (`-q`, `-qq`, and `-qqq`), or just 0 (default verbosity). These flags are useful while debugging a build when the output of the actual build invoked by `pip wheel` is required. Has no effect on the `build` backend, which produces verbose output by default.

 Platform-specific environment variables are also available:<br/>
-`CIBW_BUILD_VERBOSITY_MACOS` | `CIBW_BUILD_VERBOSITY_WINDOWS` | `CIBW_BUILD_VERBOSITY_LINUX`
+`CIBW_BUILD_VERBOSITY_MACOS` | `CIBW_BUILD_VERBOSITY_WINDOWS` | `CIBW_BUILD_VERBOSITY_LINUX` | `CIBW_BUILD_VERBOSITY_PYODIDE`

 #### Examples

@@ -1545,12 +1652,25 @@ Platform-specific environment variables are also available:<br/>
    ```


-## Command line options {: #command-line}
+## Command line {: #command-line}
+
+### Options

 ```text
 « subprocess_run("cibuildwheel", "--help") »
 ```

+### Return codes
+
+cibuildwheel exits 0 on success, or >0 if an error occurs.
+
+Specific error codes are defined:
+
+- 2 means a configuration error
+- 3 means no builds are selected (and --allow-empty wasn't passed)
+- 4 means you specified an option that has been deprecated.
+
+
 ## Placeholders

 Some options support placeholders, like `{project}`, `{package}` or `{wheel}`, that are substituted by cibuildwheel before they are used. If, for some reason, you need to write the literal name of a placeholder, e.g. literally `{project}` in a command that would ordinarily substitute `{project}`, prefix it with a hash character - `#{project}`. This is only necessary in commands where the specific string between the curly brackets would be substituted - otherwise, strings not modified.
@@ -107,6 +107,13 @@ You can override the cache folder using the ``CIBW_CACHE_PATH`` environment vari
    Download link: https://www.python.org/ftp/python/3.6.8/python-3.6.8-macosx10.9.pkg
    ```

+### Pyodide (WebAssembly) builds (experimental)
+
+Pre-requisite: you need to have a matching host version of Python (unlike all
+other cibuildwheel platforms). Linux host highly recommended; macOS hosts may
+work (e.g. invoking `pytest` directly in [`CIBW_TEST_COMMAND`](options.md#test-command) is [currently failing](https://github.com/pyodide/pyodide/issues/4802)) and Windows hosts will not work.
+
+You must target pyodide with `--platform pyodide` (or use `--only` on the identifier).

 ## Configure a CI service

@@ -154,7 +161,7 @@ To build Linux, Mac, and Windows wheels using GitHub Actions, create a `.github/
          - uses: actions/checkout@v4

          - name: Build wheels
-            run: pipx run cibuildwheel==2.17.0
+            run: pipx run cibuildwheel==2.19.1

          - uses: actions/upload-artifact@v4
            with:
@@ -188,10 +195,10 @@ To build Linux, Mac, and Windows wheels using GitHub Actions, create a `.github/
          - uses: actions/checkout@v4

          # Used to host cibuildwheel
-          - uses: actions/setup-python@v3
+          - uses: actions/setup-python@v5

          - name: Install cibuildwheel
-            run: python -m pip install cibuildwheel==2.17.0
+            run: python -m pip install cibuildwheel==2.19.1

          - name: Build wheels
            run: python -m cibuildwheel --output-dir wheelhouse
@@ -14,10 +14,10 @@ title: Working examples
 | [Tornado][]                       | ![github icon][] | ![linux icon][] ![apple icon][] ![windows icon][] | Tornado is a Python web framework and asynchronous networking library. Uses stable ABI for a small C extension. |
 | [Matplotlib][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The venerable Matplotlib, a Python library with C++ portions |
 | [NCNN][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | ncnn is a high-performance neural network inference framework optimized for the mobile platform |
+| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an analytical in-process SQL database management system |
 | [Prophet][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Tool for producing high quality forecasts for time series data that has multiple seasonality with linear or non-linear growth. |
 | [MyPy][]                          | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | The compiled version of MyPy using MyPyC. |
 | [Kivy][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Open source UI framework written in Python, running on Windows, Linux, macOS, Android and iOS |
-| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an in-process SQL OLAP Database Management System |
 | [MemRay][]                        | ![github icon][] | ![linux icon][] | Memray is a memory profiler for Python |
 | [Triton][]                        | ![github icon][] | ![linux icon][] | Self hosted runners |
 | [uvloop][]                        | ![github icon][] | ![apple icon][] ![linux icon][] | Ultra fast asyncio event loop. |
@@ -44,9 +44,9 @@ title: Working examples
 | [Implicit][]                      | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Includes GPU support for linux wheels |
 | [vispy][]                         | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Main repository for Vispy |
 | [tinyobjloader][]                 | ![azurepipelines icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Tiny but powerful single file wavefront obj loader |
+| [CTranslate2][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Includes libraries from the [Intel oneAPI toolkit](https://www.intel.com/content/www/us/en/developer/tools/oneapi/base-toolkit.html) and CUDA kernels compiled for multiple GPU architectures. |
 | [coverage.py][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The coverage tool for Python |
 | [PyCryptodome][]                  | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | A self-contained cryptographic library for Python |
-| [CTranslate2][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Includes libraries from the [Intel oneAPI toolkit](https://www.intel.com/content/www/us/en/developer/tools/oneapi/base-toolkit.html) and CUDA kernels compiled for multiple GPU architectures. |
 | [Line Profiler][]                 | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Line-by-line profiling for Python |
 | [PyYAML][]                        | ![github icon][] | ![apple icon][] | Canonical source repository for PyYAML |
 | [PyAV][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Pythonic bindings for FFmpeg's libraries. |
@@ -58,8 +58,8 @@ title: Working examples
 | [OpenColorIO][]                   | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | A color management framework for visual effects and animation. |
 | [SimpleJSON][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | simplejson is a simple, fast, extensible JSON encoder/decoder for Python  |
 | [aioquic][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | QUIC and HTTP/3 implementation in Python |
-| [ruptures][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Extensive Cython + NumPy [pyproject.toml](https://github.com/deepcharles/ruptures/blob/master/pyproject.toml) example. |
 | [Psycopg 3][]                     | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A modern implementation of a PostgreSQL adapter for Python |
+| [ruptures][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Extensive Cython + NumPy [pyproject.toml](https://github.com/deepcharles/ruptures/blob/master/pyproject.toml) example. |
 | [OpenTimelineIO][]                | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Open Source API and interchange format for editorial timeline information. |
 | [PyTables][]                      | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python package to manage extremely large amounts of data |
 | [Parselmouth][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python interface to the Praat software package, using pybind11, C++17 and CMake, with the core Praat static library built only once and shared between wheels. |
@@ -69,20 +69,20 @@ title: Working examples
 | [H3-py][]                         | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Python bindings for H3, a hierarchical hexagonal geospatial indexing system |
 | [mosec][]                         | ![github icon][] | ![linux icon][] ![apple icon][] | A machine learning model serving framework powered by Rust |
 | [Picologging][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A high-performance logging library for Python. |
+| [time-machine][]                  | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Time mocking library using only the CPython C API. |
 | [markupsafe][]                    | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Safely add untrusted strings to HTML/XML markup. |
 | [Rtree][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Rtree: spatial index for Python GIS |
-| [time-machine][]                  | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Time mocking library using only the CPython C API. |
 | [pybind11 cmake_example][]        | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Example pybind11 module built with a CMake-based build system |
 | [KDEpy][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Kernel Density Estimation in Python |
-| [python-rapidjson][]              | ![travisci icon][] ![gitlab icon][] ![appveyor icon][] | ![windows icon][] ![linux icon][] | Python wrapper around rapidjson |
 | [dd-trace-py][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Uses custom alternate arch emulation on GitHub |
-| [python-snappy][]                 | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Python bindings for the snappy google library |
+| [python-rapidjson][]              | ![travisci icon][] ![gitlab icon][] ![appveyor icon][] | ![windows icon][] ![linux icon][] | Python wrapper around rapidjson |
 | [tgcalls][]                       | ![github icon][] | ![apple icon][] ![windows icon][] | Python `pybind11` binding to Telegram's WebRTC library with third party dependencies like `OpenSSL`, `MozJPEG`, `FFmpeg`, etc. |
+| [python-snappy][]                 | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Python bindings for the snappy google library |
 | [pybind11 python_example][]       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Example pybind11 module built with a Python-based build system |
-| [sourmash][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Quickly search, compare, and analyze genomic and metagenomic data sets. |
 | [abess][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A fast best-subset selection library. It uses cibuildwheel to build a large project with C++ extensions. |
-| [matrixprofile][]                 | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python 3 library making time series data mining tasks, utilizing matrix profile algorithms, accessible to everyone. |
+| [sourmash][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Quickly search, compare, and analyze genomic and metagenomic data sets. |
 | [cyvcf2][]                        | ![github icon][] | ![apple icon][] ![linux icon][] | cython + htslib == fast VCF and BCF processing |
+| [matrixprofile][]                 | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python 3 library making time series data mining tasks, utilizing matrix profile algorithms, accessible to everyone. |
 | [jq.py][]                         | ![travisci icon][] | ![apple icon][] ![linux icon][] | Python bindings for jq |
 | [iminuit][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Jupyter-friendly Python interface for C++ MINUIT2 |
 | [Tokenizer][]                     | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Fast and customizable text tokenization library with BPE and SentencePiece support |
@@ -94,39 +94,39 @@ title: Working examples
 | [bx-python][]                     | ![travisci icon][] | ![apple icon][] ![linux icon][] | A library that includes Cython extensions. |
 | [boost-histogram][]               | ![github icon][] ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Supports full range of wheels, including PyPy and alternate archs. |
 | [Python-WebRTC][]                 | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | a Python extension that provides bindings to WebRTC M92 |
-| [pybase64][]                      | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Fast Base64 encoding/decoding in Python |
 | [power-grid-model][]              | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Python/C++ library for distribution power system analysis |
+| [pybase64][]                      | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Fast Base64 encoding/decoding in Python |
 | [fathon][]                        | ![travisci icon][] | ![apple icon][] ![linux icon][] | python package for DFA (Detrended Fluctuation Analysis) and related algorithms |
-| [Arbor][]                         | ![github icon][] | ![apple icon][] ![linux icon][] | Arbor is a multi-compartment neuron simulation library; compatible with next-generation accelerators; best-practices applied to research software; focused on community-driven development. Includes a [small script](https://github.com/arbor-sim/arbor/blob/master/scripts/patchwheel.py) patching `rpath` in bundled libraries.  |
 | [Imagecodecs (fork)][]            | ![azurepipelines icon][] | ![apple icon][] ![linux icon][] | Over 20 external dependencies in compiled libraries, custom docker image, `libomp`, `openblas` and `install_name_tool` for macOS. |
+| [Arbor][]                         | ![github icon][] | ![apple icon][] ![linux icon][] | Arbor is a multi-compartment neuron simulation library; compatible with next-generation accelerators; best-practices applied to research software; focused on community-driven development. Includes a [small script](https://github.com/arbor-sim/arbor/blob/master/scripts/patchwheel.py) patching `rpath` in bundled libraries.  |
 | [pybind11 scikit_build_example][] | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | An example combining scikit-build and pybind11 |
 | [polaroid][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Full range of wheels for setuptools rust, with auto release and PyPI deploy. |
-| [etebase-py][]                    | ![travisci icon][] | ![linux icon][] | Python bindings to a Rust library using `setuptools-rust`, and `sccache` for improved speed. |
 | [clang-format][]                  | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Scikit-build wrapper around LLVM's CMake, all platforms, generic wheels. |
+| [etebase-py][]                    | ![travisci icon][] | ![linux icon][] | Python bindings to a Rust library using `setuptools-rust`, and `sccache` for improved speed. |
 | [cf-units][]                      | ![github icon][] | ![apple icon][] ![linux icon][] | Units of measure as required by the Climate and Forecast (CF) Metadata Conventions |
 | [ninja][]                         | ![github icon][] ![travisci icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Multitagged binary builds for all supported platforms, using cibw 2 config configuration. |
 | [numpythia][]                     | ![github icon][] | ![apple icon][] ![linux icon][] | The interface between PYTHIA and NumPy |
 | [pyjet][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The interface between FastJet and NumPy |
 | [ril][]                           | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A python binding to Rust Imaging library using maturin and Pyo3, utilizes Github Action cache to improve speed. Builds abi3 wheels. |
-| [GSD][]                           | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Cython and NumPy project with 64-bit wheels. |
 | [SiPM][]                          | ![github icon][] | ![apple icon][] ![linux icon][] | High performance library for SiPM detectors simulation using C++17, OpenMP and AVX2 intrinsics. |
-| [xmlstarlet][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Python 3.6+ CFFI bindings with true MSVC build. |
+| [GSD][]                           | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Cython and NumPy project with 64-bit wheels. |
 | [CorrectionLib][]                 | ![github icon][] | ![apple icon][] ![linux icon][] | Structured JSON powered correction library for HEP, designed for the CMS experiment at CERN. |
 | [aalink][]                        | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Async Python interface for Ableton Link. |
+| [xmlstarlet][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Python 3.6+ CFFI bindings with true MSVC build. |
 | [pyinstrument_cext][]             | ![travisci icon][] ![appveyor icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A simple C extension, without external dependencies |
 | [werpy][]                         | ![github icon][] | ![windows icon][] ![linux icon][] ![apple icon][] | An ultra-fast python package using optimized dynamic programming to compute the Word Error Rate (WER). |
 | [pybind11 cross build example][]  | ![github icon][] ![gitlab icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Same as pybind11 cmake_example but used to demo Linux ARM + Windows + macOS builds on GitLab |

 [scikit-learn]: https://github.com/scikit-learn/scikit-learn
-[pytorch-fairseq]: https://github.com/pytorch/fairseq
+[pytorch-fairseq]: https://github.com/facebookresearch/fairseq
 [NumPy]: https://github.com/numpy/numpy
 [Tornado]: https://github.com/tornadoweb/tornado
 [Matplotlib]: https://github.com/matplotlib/matplotlib
 [NCNN]: https://github.com/Tencent/ncnn
+[duckdb]: https://github.com/duckdb/duckdb
 [Prophet]: https://github.com/facebook/prophet
 [MyPy]: https://github.com/mypyc/mypy_mypyc-wheels
 [Kivy]: https://github.com/kivy/kivy
-[duckdb]: https://github.com/duckdb/duckdb
 [MemRay]: https://github.com/bloomberg/memray
 [Triton]: https://github.com/openai/triton
 [uvloop]: https://github.com/MagicStack/uvloop
@@ -141,11 +141,11 @@ title: Working examples
 [twisted-iocpsupport]: https://github.com/twisted/twisted-iocpsupport
 [PyOxidizer]: https://github.com/indygreg/PyOxidizer
 [cvxpy]: https://github.com/cvxpy/cvxpy
-[websockets]: https://github.com/aaugustin/websockets
+[websockets]: https://github.com/python-websockets/websockets
 [pedalboard]: https://github.com/spotify/pedalboard
 [River]: https://github.com/online-ml/river
 [UltraJSON]: https://github.com/ultrajson/ultrajson
-[OpenSpiel]: https://github.com/deepmind/open_spiel
+[OpenSpiel]: https://github.com/google-deepmind/open_spiel
 [aiortc]: https://github.com/aiortc/aiortc
 [Confluent client for Kafka]: https://github.com/confluentinc/confluent-kafka-python
 [Dependency Injector]: https://github.com/ets-labs/python-dependency-injector
@@ -153,9 +153,9 @@ title: Working examples
 [Implicit]: https://github.com/benfred/implicit
 [vispy]: https://github.com/vispy/vispy
 [tinyobjloader]: https://github.com/tinyobjloader/tinyobjloader
+[CTranslate2]: https://github.com/OpenNMT/CTranslate2
 [coverage.py]: https://github.com/nedbat/coveragepy
 [PyCryptodome]: https://github.com/Legrandin/pycryptodome
-[CTranslate2]: https://github.com/OpenNMT/CTranslate2
 [Line Profiler]: https://github.com/pyutils/line_profiler
 [PyYAML]: https://github.com/yaml/pyyaml
 [PyAV]: https://github.com/PyAV-Org/PyAV
@@ -167,9 +167,9 @@ title: Working examples
 [OpenColorIO]: https://github.com/AcademySoftwareFoundation/OpenColorIO
 [SimpleJSON]: https://github.com/simplejson/simplejson
 [aioquic]: https://github.com/aiortc/aioquic
-[ruptures]: https://github.com/deepcharles/ruptures
 [Psycopg 3]: https://github.com/psycopg/psycopg
-[OpenTimelineIO]: https://github.com/PixarAnimationStudios/OpenTimelineIO
+[ruptures]: https://github.com/deepcharles/ruptures
+[OpenTimelineIO]: https://github.com/AcademySoftwareFoundation/OpenTimelineIO
 [PyTables]: https://github.com/PyTables/PyTables
 [Parselmouth]: https://github.com/YannickJadoul/Parselmouth
 [google neuroglancer]: https://github.com/google/neuroglancer
@@ -178,20 +178,20 @@ title: Working examples
 [H3-py]: https://github.com/uber/h3-py
 [mosec]: https://github.com/mosecorg/mosec
 [Picologging]: https://github.com/microsoft/picologging
+[time-machine]: https://github.com/adamchainz/time-machine
 [markupsafe]: https://github.com/pallets/markupsafe
 [Rtree]: https://github.com/Toblerity/rtree
-[time-machine]: https://github.com/adamchainz/time-machine
 [pybind11 cmake_example]: https://github.com/pybind/cmake_example
 [KDEpy]: https://github.com/tommyod/KDEpy
-[python-rapidjson]: https://github.com/python-rapidjson/python-rapidjson
 [dd-trace-py]: https://github.com/DataDog/dd-trace-py
-[python-snappy]: https://github.com/andrix/python-snappy
+[python-rapidjson]: https://github.com/python-rapidjson/python-rapidjson
 [tgcalls]: https://github.com/MarshalX/tgcalls
+[python-snappy]: https://github.com/intake/python-snappy
 [pybind11 python_example]: https://github.com/pybind/python_example
-[sourmash]: https://github.com/dib-lab/sourmash
 [abess]: https://github.com/abess-team/abess
-[matrixprofile]: https://github.com/matrix-profile-foundation/matrixprofile
+[sourmash]: https://github.com/sourmash-bio/sourmash
 [cyvcf2]: https://github.com/brentp/cyvcf2
+[matrixprofile]: https://github.com/matrix-profile-foundation/matrixprofile
 [jq.py]: https://github.com/mwilliamson/jq.py
 [iminuit]: https://github.com/scikit-hep/iminuit
 [Tokenizer]: https://github.com/OpenNMT/Tokenizer
@@ -203,25 +203,25 @@ title: Working examples
 [bx-python]: https://github.com/bxlab/bx-python
 [boost-histogram]: https://github.com/scikit-hep/boost-histogram
 [Python-WebRTC]: https://github.com/MarshalX/python-webrtc
+[power-grid-model]: https://github.com/PowerGridModel/power-grid-model
 [pybase64]: https://github.com/mayeut/pybase64
-[power-grid-model]: https://github.com/alliander-opensource/power-grid-model
 [fathon]: https://github.com/stfbnc/fathon
-[Arbor]: https://github.com/arbor-sim/arbor
 [Imagecodecs (fork)]: https://github.com/czaki/imagecodecs_build
+[Arbor]: https://github.com/arbor-sim/arbor
 [pybind11 scikit_build_example]: https://github.com/pybind/scikit_build_example
 [polaroid]: https://github.com/daggy1234/polaroid
-[etebase-py]: https://github.com/etesync/etebase-py
 [clang-format]: https://github.com/ssciwr/clang-format-wheel
+[etebase-py]: https://github.com/etesync/etebase-py
 [cf-units]: https://github.com/SciTools/cf-units
 [ninja]: https://github.com/scikit-build/ninja-python-distributions
 [numpythia]: https://github.com/scikit-hep/numpythia
 [pyjet]: https://github.com/scikit-hep/pyjet
 [ril]: https://github.com/Cryptex-github/ril-py
-[GSD]: https://github.com/glotzerlab/gsd
 [SiPM]: https://github.com/EdoPro98/SimSiPM
-[xmlstarlet]: https://github.com/dimitern/xmlstarlet
+[GSD]: https://github.com/glotzerlab/gsd
 [CorrectionLib]: https://github.com/cms-nanoAOD/correctionlib
 [aalink]: https://github.com/artfwo/aalink
+[xmlstarlet]: https://github.com/dimitern/xmlstarlet
 [pyinstrument_cext]: https://github.com/joerick/pyinstrument_cext
 [werpy]: https://github.com/analyticsinmotion/werpy
 [pybind11 cross build example]: https://github.com/wbarnha/pybind_cmake_example_crossbuild
@@ -12,7 +12,7 @@ stack: python 3.7
 init:
 - cmd: set PATH=C:\Python37;C:\Python37\Scripts;%PATH%

-install: python -m pip install cibuildwheel==2.17.0
+install: python -m pip install cibuildwheel==2.19.1

 build_script: python -m cibuildwheel --output-dir wheelhouse

@@ -6,7 +6,7 @@ jobs:
    - bash: |
        set -o errexit
        python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==2.17.0
+        pip3 install cibuildwheel==2.19.1
      displayName: Install dependencies
    - bash: cibuildwheel --output-dir wheelhouse .
      displayName: Build wheels
@@ -20,7 +20,7 @@ jobs:
    - bash: |
        set -o errexit
        python3 -m pip install --upgrade pip
-        python3 -m pip install cibuildwheel==2.17.0
+        python3 -m pip install cibuildwheel==2.19.1
      displayName: Install dependencies
    - bash: cibuildwheel --output-dir wheelhouse .
      displayName: Build wheels
@@ -34,7 +34,7 @@ jobs:
    - bash: |
        set -o errexit
        python -m pip install --upgrade pip
-        pip install cibuildwheel==2.17.0
+        pip install cibuildwheel==2.19.1
      displayName: Install dependencies
    - bash: cibuildwheel --output-dir wheelhouse .
      displayName: Build wheels
@@ -11,7 +11,7 @@ jobs:
      - run:
          name: Build the Linux wheels.
          command: |
-            pip3 install --user cibuildwheel==2.17.0
+            pip3 install --user cibuildwheel==2.19.1
            cibuildwheel --output-dir wheelhouse
      - store_artifacts:
          path: wheelhouse/
@@ -28,7 +28,7 @@ jobs:
      - run:
          name: Build the Linux aarch64 wheels.
          command: |
-            python3 -m pip install --user cibuildwheel==2.17.0
+            python3 -m pip install --user cibuildwheel==2.19.1
            python3 -m cibuildwheel --output-dir wheelhouse
      - store_artifacts:
          path: wheelhouse/
@@ -42,7 +42,7 @@ jobs:
      - run:
          name: Build the OS X wheels.
          command: |
-            pip3 install cibuildwheel==2.17.0
+            pip3 install cibuildwheel==2.19.1
            cibuildwheel --output-dir wheelhouse
      - store_artifacts:
          path: wheelhouse/
@@ -1,6 +1,6 @@
 build_and_store_wheels: &BUILD_AND_STORE_WHEELS
  install_cibuildwheel_script:
-    - python -m pip install cibuildwheel==2.17.0
+    - python -m pip install cibuildwheel==2.19.1
  run_cibuildwheel_script:
    - cibuildwheel
  wheels_artifacts:
@@ -1,6 +1,6 @@
 build_and_store_wheels: &BUILD_AND_STORE_WHEELS
  install_cibuildwheel_script:
-    - python -m pip install cibuildwheel==2.17.0
+    - python -m pip install cibuildwheel==2.19.1
  run_cibuildwheel_script:
    - cibuildwheel
  wheels_artifacts:
@@ -23,7 +23,7 @@ jobs:
      - uses: actions/checkout@v4

      - name: Build wheels
-        uses: pypa/cibuildwheel@v2.17.0
+        uses: pypa/cibuildwheel@v2.19.1

      - uses: actions/upload-artifact@v4
        with:
@@ -15,7 +15,7 @@ jobs:
      - uses: actions/checkout@v4

      - name: Build wheels
-        uses: pypa/cibuildwheel@v2.17.0
+        uses: pypa/cibuildwheel@v2.19.1
        # env:
        #   CIBW_SOME_OPTION: value
        #    ...
@@ -21,7 +21,7 @@ jobs:
          platforms: all

      - name: Build wheels
-        uses: pypa/cibuildwheel@v2.17.0
+        uses: pypa/cibuildwheel@v2.19.1
        env:
          # configure cibuildwheel to build native archs ('auto'), and some
          # emulated ones
@@ -12,7 +12,7 @@ linux:
    DOCKER_TLS_CERTDIR: ""
  script:
    - curl -sSL https://get.docker.com/ | sh
-    - python -m pip install cibuildwheel==2.17.0
+    - python -m pip install cibuildwheel==2.19.1
    - cibuildwheel --output-dir wheelhouse
  artifacts:
    paths:
@@ -23,7 +23,7 @@ windows:
  before_script:
    - choco install python -y --version 3.8.6
    - choco install git.install -y
-    - py -m pip install cibuildwheel==2.17.0
+    - py -m pip install cibuildwheel==2.19.1
  script:
    - py -m cibuildwheel --output-dir wheelhouse --platform windows
  artifacts:
@@ -14,7 +14,7 @@ linux:
    - curl -sSL https://get.docker.com/ | sh
    # Warning: This is extremely slow, be careful with how many wheels you build
    - docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
-    - python -m pip install cibuildwheel==2.17.0
+    - python -m pip install cibuildwheel==2.19.1
    # Assuming your CI runner's default architecture is x86_64...
    - cibuildwheel --output-dir wheelhouse --platform linux --archs aarch64
  artifacts:
@@ -20,7 +20,7 @@ jobs:
        - ln -s /c/Python38/python.exe /c/Python38/python3.exe

 install:
-  - python3 -m pip install cibuildwheel==2.17.0
+  - python3 -m pip install cibuildwheel==2.19.1

 script:
  # build the wheels, put them into './dist'
@@ -26,7 +26,7 @@ jobs:
        - ln -s /c/Python38/python.exe /c/Python38/python3.exe

 install:
-  - python3 -m pip install cibuildwheel==2.17.0
+  - python3 -m pip install cibuildwheel==2.19.1

 script:
  # build the wheels, put them into './wheelhouse'
@@ -54,7 +54,7 @@ jobs:
    - stage: deploy
      name: Build and deploy Linux wheels
      services: docker
-      install: python3 -m pip install cibuildwheel==2.17.0 twine
+      install: python3 -m pip install cibuildwheel==2.19.1 twine
      script: python3 -m cibuildwheel --output-dir wheelhouse
      after_success: python3 -m twine upload --skip-existing wheelhouse/*.whl
    # Deploy on windows
@@ -62,7 +62,7 @@ jobs:
      name: Build and deploy Windows wheels
      os: windows
      language: shell
-      install: python3 -m pip install cibuildwheel==2.17.0 twine
+      install: python3 -m pip install cibuildwheel==2.19.1 twine
      script: python3 -m cibuildwheel --output-dir wheelhouse
      after_success: python3 -m twine upload --skip-existing wheelhouse/*.whl

@@ -49,3 +49,5 @@ plugins:
      module_name: docs/main
      j2_variable_start_string: «
      j2_variable_end_string: »
+      on_error_fail: true
+      on_undefined: strict
@@ -4,17 +4,21 @@ import os
 import shutil
 import sys
 from pathlib import Path
+from typing import Any

 import nox

+nox.needs_version = ">=2024.4.15"
 nox.options.sessions = ["lint", "pylint", "check_manifest", "tests"]
-
-PYTHON_ALL_VERSIONS = ["3.7", "3.8", "3.9", "3.10", "3.11", "3.12"]
+nox.options.default_venv_backend = "uv|virtualenv"

 DIR = Path(__file__).parent.resolve()

-if os.environ.get("CI", None):
-    nox.options.error_on_missing_interpreters = True
+
+def install_and_run(session: nox.Session, script: str, *args: str, **kwargs: Any) -> str | None:
+    deps = nox.project.load_toml(script)["dependencies"]
+    session.install(*deps)
+    return session.run("python", script, *args, **kwargs)


@nox.session
@@ -22,11 +26,11 @@ def tests(session: nox.Session) -> None:
    """
    Run the unit and regular tests.
    """
-    unit_test_args = ["--run-docker"] if sys.platform.startswith("linux") else []
-    session.install("-e", ".[test]")
+    session.install("-e.[test]")
    if session.posargs:
        session.run("pytest", *session.posargs)
    else:
+        unit_test_args = ["--run-docker"] if sys.platform.startswith("linux") else []
        session.run("pytest", "unit_test", *unit_test_args)
        session.run("pytest", "test", "-x", "--durations", "0", "--timeout=2400", "test")

@@ -46,7 +50,7 @@ def pylint(session: nox.Session) -> None:
    Run pylint.
    """

-    session.install("pylint", ".")
+    session.install("pylint>=3.2", "-e.")
    session.run("pylint", "cibuildwheel", *session.posargs)


@@ -60,31 +64,57 @@ def check_manifest(session: nox.Session) -> None:
    session.run("check-manifest", *session.posargs)


-@nox.session(python=PYTHON_ALL_VERSIONS)
+@nox.session
 def update_constraints(session: nox.Session) -> None:
    """
    Update the dependencies inplace.
    """
-    session.install("pip-tools")
-    assert isinstance(session.python, str)
-    python_version = session.python.replace(".", "")
-    env = os.environ.copy()
-    # CUSTOM_COMPILE_COMMAND is a pip-compile option that tells users how to
-    # regenerate the constraints files
-    env["CUSTOM_COMPILE_COMMAND"] = f"nox -s {session.name}"
-    session.run(
-        "pip-compile",
-        "--allow-unsafe",
-        "--upgrade",
-        "cibuildwheel/resources/constraints.in",
-        f"--output-file=cibuildwheel/resources/constraints-python{python_version}.txt",
-        env=env,
+
+    resources = Path("cibuildwheel/resources")
+
+    if session.venv_backend != "uv":
+        session.install("uv>=0.1.23")
+
+    for minor_version in range(7, 14):
+        python_version = f"3.{minor_version}"
+        env = os.environ.copy()
+        # CUSTOM_COMPILE_COMMAND is a pip-compile option that tells users how to
+        # regenerate the constraints files
+        env["UV_CUSTOM_COMPILE_COMMAND"] = f"nox -s {session.name}"
+        output_file = resources / f"constraints-python{python_version.replace('.', '')}.txt"
+        session.run(
+            "uv",
+            "pip",
+            "compile",
+            f"--python-version={python_version}",
+            "--upgrade",
+            resources / "constraints.in",
+            f"--output-file={output_file}",
+            env=env,
+        )
+
+    shutil.copyfile(
+        resources / "constraints-python312.txt",
+        resources / "constraints.txt",
    )
-    if session.python == PYTHON_ALL_VERSIONS[-1]:
-        RESOURCES = DIR / "cibuildwheel" / "resources"
-        shutil.copyfile(
-            RESOURCES / f"constraints-python{python_version}.txt",
-            RESOURCES / "constraints.txt",
+
+    build_platforms = nox.project.load_toml(resources / "build-platforms.toml")
+    pyodides = build_platforms["pyodide"]["python_configurations"]
+    for pyodide in pyodides:
+        python_version = ".".join(pyodide["version"].split(".")[:2])
+        pyodide_version = pyodide["pyodide_version"]
+        output_file = resources / f"constraints-pyodide{python_version.replace('.', '')}.txt"
+        tmp_file = Path(session.create_tmp()) / "constraints-pyodide.in"
+        tmp_file.write_text(f"pip\nbuild[virtualenv]\npyodide-build=={pyodide_version}")
+        session.run(
+            "uv",
+            "pip",
+            "compile",
+            f"--python-version={python_version}",
+            "--upgrade",
+            tmp_file,
+            f"--output-file={output_file}",
+            env=env,
        )


@@ -93,20 +123,20 @@ def update_pins(session: nox.Session) -> None:
    """
    Update the python, docker and virtualenv pins version inplace.
    """
-    session.install("-e", ".[bin]")
+    session.install("-e.[bin]")
    session.run("python", "bin/update_pythons.py", "--force")
    session.run("python", "bin/update_docker.py")
    session.run("python", "bin/update_virtualenv.py", "--force")
+    session.run("python", "bin/update_nodejs.py", "--force")


-@nox.session
+@nox.session(reuse_venv=True)
 def update_proj(session: nox.Session) -> None:
    """
    Update the README inplace.
    """
-    session.install("-e", ".[bin]")
-    session.run(
-        "python",
+    install_and_run(
+        session,
        "bin/projects.py",
        "docs/data/projects.yml",
        *session.posargs,
@@ -118,27 +148,26 @@ def generate_schema(session: nox.Session) -> None:
    """
    Generate the cibuildwheel.schema.json file.
    """
-    session.install("pyyaml")
-    output = session.run("python", "bin/generate_schema.py", silent=True)
+    output = install_and_run(session, "bin/generate_schema.py", silent=True)
    assert isinstance(output, str)
    DIR.joinpath("cibuildwheel/resources/cibuildwheel.schema.json").write_text(output)


-@nox.session(python="3.9")
+@nox.session(reuse_venv=True)
+def bump_version(session: nox.Session) -> None:
+    """
+    Bump cibuildwheel's version. Interactive.
+    """
+    install_and_run(session, "bin/bump_version.py")
+
+
+@nox.session(python="3.12")
 def docs(session: nox.Session) -> None:
    """
-    Build the docs.
+    Build the docs. Will serve unless --non-interactive
    """
-    session.install("-e", ".[docs]")
-    session.run("pip", "list")
-
-    if session.posargs:
-        if "serve" in session.posargs:
-            session.run("mkdocs", "serve")
-        else:
-            session.error("Unrecognized args, use 'serve'")
-    else:
-        session.run("mkdocs", "build")
+    session.install("-e.[docs]")
+    session.run("mkdocs", "serve" if session.interactive else "build", "--strict", *session.posargs)


@nox.session
@@ -1,13 +1,104 @@
 [build-system]
-requires = [
-    "setuptools>=42",
-]
-build-backend = "setuptools.build_meta"
+requires = ["hatchling"]
+build-backend = "hatchling.build"

+[project]
+name = "cibuildwheel"
+version = "2.19.1"
+description = "Build Python wheels on CI with minimal configuration."
+readme = "README.md"
+license = "BSD-2-Clause"
+requires-python = ">=3.8"
+authors = [
+    { name = "Joe Rickerby", email = "joerick@mac.com" },
+]
+keywords = [
+    "appveyor",
+    "ci",
+    "linux",
+    "macos",
+    "packaging",
+    "pypi",
+    "travis",
+    "wheel",
+    "windows",
+]
+classifiers = [
+    "Development Status :: 5 - Production/Stable",
+    "Intended Audience :: Developers",
+    "License :: OSI Approved :: BSD License",
+    "Natural Language :: English",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3 :: Only",
+    "Programming Language :: Python :: 3.8",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: Implementation :: CPython",
+    "Topic :: Software Development :: Build Tools",
+]
+dependencies = [
+    "bashlex!=0.13",
+    "bracex",
+    "certifi",
+    "filelock",
+    "packaging>=20.9",
+    "platformdirs",
+    "tomli;python_version < '3.11'",
+    "typing-extensions>=4.1.0;python_version < '3.11'",
+]
+
+[project.optional-dependencies]
+bin = [
+    "click",
+    "packaging>=21.0",
+    "pip-tools",
+    "pygithub",
+    "pyyaml",
+    "requests",
+    "rich>=9.6",
+]
+dev = [
+    "cibuildwheel[test,bin]",
+]
+docs = [
+    "jinja2>=3.1.2",
+    "mkdocs-include-markdown-plugin==2.8.0",
+    "mkdocs-macros-plugin",
+    "mkdocs==1.3.1",
+    "pymdown-extensions",
+]
+test = [
+    "build",
+    "jinja2",
+    "pytest-timeout",
+    "pytest-xdist",
+    "pytest>=6",
+    "tomli_w",
+    "validate-pyproject",
+]
+uv = ["uv"]
+
+[project.scripts]
+cibuildwheel = "cibuildwheel.__main__:main"
+
+[project.entry-points."validate_pyproject.tool_schema"]
+cibuildwheel = "cibuildwheel.schema:get_schema"
+
+[project.urls]
+Changelog = "https://github.com/pypa/cibuildwheel#changelog"
+Documentation = "https://cibuildwheel.pypa.io"
+Homepage = "https://github.com/pypa/cibuildwheel"

 [tool.pytest.ini_options]
 minversion = "6.0"
-addopts = ["-ra", "--showlocals", "--strict-markers", "--strict-config"]
+addopts = [
+  "-rfEsX",  # TODO: replace with -ra when pytest > 8.2.2 is released
+  "--showlocals",
+  "--strict-markers",
+  "--strict-config",
+]
 junit_family = "xunit2"
 xfail_strict = true
 filterwarnings = ["error"]
@@ -57,21 +148,6 @@ module = [
 ignore_missing_imports = true


-[tool.check-manifest]
-ignore = [
-    ".*",
-    ".circleci/**",
-    "test/**",
-    "unit_test/**",
-    "docs/**",
-    "examples/**",
-    "bin/**",
-    "*.yml",
-    "CI.md",  # TODO: can change test/test_ssl and remove this
-    "requirements-dev.txt",
-    "noxfile.py",
-]
-
 [tool.pylint]
 py-version = "3.8"
 jobs = "0"
@@ -106,6 +182,7 @@ messages_control.disable = [
  "wrong-import-position",
  "unused-argument",  # Handled by Ruff
  "broad-exception-raised",  # Could be improved eventually
+  "consider-using-in",  # MyPy can't narrow "in"
 ]

 [tool.ruff]
@@ -162,6 +239,7 @@ flake8-unused-arguments.ignore-variadic-names = true
 [tool.ruff.lint.per-file-ignores]
 "unit_test/*" = ["PLC1901"]
 "cibuildwheel/_compat/**.py" = ["TID251"]
+"bin/*" = ["TID251"]

 [tool.repo-review]
 ignore = ["PC170", "PP303"]
@@ -1,57 +0,0 @@
-[metadata]
-name = cibuildwheel
-version = 2.17.0
-description = Build Python wheels on CI with minimal configuration.
-long_description = file: README.md
-long_description_content_type = text/markdown
-url = https://github.com/pypa/cibuildwheel
-author = Joe Rickerby
-author_email = joerick@mac.com
-license = BSD-2-Clause
-license_files = LICENSE
-classifiers =
-    Development Status :: 5 - Production/Stable
-    Intended Audience :: Developers
-    License :: OSI Approved :: BSD License
-    Natural Language :: English
-    Programming Language :: Python :: 3
-    Programming Language :: Python :: 3 :: Only
-    Programming Language :: Python :: 3.8
-    Programming Language :: Python :: 3.9
-    Programming Language :: Python :: 3.10
-    Programming Language :: Python :: 3.11
-    Programming Language :: Python :: 3.12
-    Programming Language :: Python :: Implementation :: CPython
-    Topic :: Software Development :: Build Tools
-keywords = ci,wheel,packaging,pypi,travis,appveyor,macos,linux,windows
-project_urls =
-    Changelog=https://github.com/pypa/cibuildwheel#changelog
-    Documentation=https://cibuildwheel.pypa.io/
-
-[options]
-packages = find:
-install_requires =
-    bashlex!=0.13
-    bracex
-    certifi
-    filelock
-    packaging>=20.9
-    platformdirs
-    tomli;python_version < '3.11'
-    typing-extensions>=4.1.0;python_version < '3.11'
-python_requires = >=3.8
-include_package_data = True
-zip_safe = False
-
-[options.packages.find]
-include =
-    cibuildwheel
-
-[options.entry_points]
-console_scripts =
-    cibuildwheel = cibuildwheel.__main__:main
-validate_pyproject.tool_schema =
-    cibuildwheel = cibuildwheel.schema:get_schema
-
-[options.package_data]
-cibuildwheel = resources/*
@@ -1,38 +0,0 @@
-from __future__ import annotations
-
-from setuptools import setup
-
-extras = {
-    "docs": [
-        "mkdocs-include-markdown-plugin==2.8.0",
-        "mkdocs==1.3.1",
-        "jinja2>=3.1.2",
-        "pymdown-extensions",
-        "mkdocs-macros-plugin",
-    ],
-    "test": [
-        "jinja2",
-        "pytest>=6",
-        "pytest-timeout",
-        "pytest-xdist",
-        "build",
-        "tomli_w",
-        "validate-pyproject",
-    ],
-    "bin": [
-        "click",
-        "pip-tools",
-        "pygithub",
-        "pyyaml",
-        "requests",
-        "rich>=9.6",
-        "packaging>=21.0",
-    ],
-}
-
-extras["dev"] = [
-    *extras["test"],
-    *extras["bin"],
-]
-
-setup(extras_require=extras)
@@ -6,14 +6,18 @@ from typing import Generator

 import pytest

-from cibuildwheel.util import detect_ci_provider
+from cibuildwheel.util import detect_ci_provider, find_uv

-from .utils import platform
+from .utils import EMULATED_ARCHS, platform


 def pytest_addoption(parser) -> None:
    parser.addoption(
-        "--run-emulation", action="store_true", default=False, help="run emulation tests"
+        "--run-emulation",
+        action="store",
+        default=None,
+        help="run emulation tests",
+        choices=("all", *EMULATED_ARCHS),
    )
    parser.addoption("--run-podman", action="store_true", default=False, help="run podman tests")
    parser.addoption(
@@ -27,10 +31,21 @@ def pytest_addoption(parser) -> None:
@pytest.fixture(
    params=[{"CIBW_BUILD_FRONTEND": "pip"}, {"CIBW_BUILD_FRONTEND": "build"}], ids=["pip", "build"]
 )
-def build_frontend_env(request) -> dict[str, str]:
+def build_frontend_env_nouv(request) -> dict[str, str]:
+    if platform == "pyodide":
+        pytest.skip("Can't use pip as build frontend for pyodide platform")
+
    return request.param  # type: ignore[no-any-return]


+@pytest.fixture()
+def build_frontend_env(build_frontend_env_nouv: dict[str, str]) -> dict[str, str]:
+    if build_frontend_env_nouv["CIBW_BUILD_FRONTEND"] == "build" and find_uv() is not None:
+        return {"CIBW_BUILD_FRONTEND": "build[uv]"}
+
+    return build_frontend_env_nouv
+
+
@pytest.fixture()
 def docker_cleanup() -> Generator[None, None, None]:
    def get_images() -> set[str]:
@@ -4,12 +4,23 @@ import textwrap

 from . import test_projects, utils

+pyproject_toml = r"""
+[build-system]
+requires = ["setuptools", "wheel"]
+build-backend = "setuptools.build_meta"
+"""
+
 limited_api_project = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(
        r"""
+        import sysconfig
+
+        IS_CPYTHON = sys.implementation.name == "cpython"
+        Py_GIL_DISABLED = sysconfig.get_config_var("Py_GIL_DISABLED")
+        CAN_USE_ABI3 = IS_CPYTHON and not Py_GIL_DISABLED
        cmdclass = {}
        extension_kwargs = {}
-        if sys.version_info[:2] >= (3, 8):
+        if CAN_USE_ABI3 and sys.version_info[:2] >= (3, 10):
            from wheel.bdist_wheel import bdist_wheel as _bdist_wheel

            class bdist_wheel_abi3(_bdist_wheel):
@@ -22,7 +33,7 @@ limited_api_project = test_projects.new_c_project(
                    return python, "abi3", plat

            cmdclass["bdist_wheel"] = bdist_wheel_abi3
-            extension_kwargs["define_macros"] = [("Py_LIMITED_API", "0x03080000")]
+            extension_kwargs["define_macros"] = [("Py_LIMITED_API", "0x030A0000")]
            extension_kwargs["py_limited_api"] = True
    """
    ),
@@ -30,25 +41,39 @@ limited_api_project = test_projects.new_c_project(
    setup_py_setup_args_add="cmdclass=cmdclass",
 )

+limited_api_project.files["pyproject.toml"] = pyproject_toml
+

 def test_abi3(tmp_path):
    project_dir = tmp_path / "project"
    limited_api_project.generate(project_dir)

+    single_python_tag = "cp{}{}".format(*utils.SINGLE_PYTHON_VERSION)
+
    # build the wheels
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_SKIP": "pp* ",  # PyPy does not have a Py_LIMITED_API equivalent
+            # free_threaded and PyPy do not have a Py_LIMITED_API equivalent, just build one of those
+            # also limit the number of builds for test performance reasons
+            "CIBW_BUILD": f"cp39-* cp310-* pp310-* {single_python_tag}-* cp313t-*"
        },
    )

    # check that the expected wheels are produced
-    expected_wheels = [
-        w.replace("cp38-cp38", "cp38-abi3")
-        for w in utils.expected_wheels("spam", "0.1.0")
-        if "-pp" not in w and "-cp39" not in w and "-cp31" not in w
-    ]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    if utils.platform == "pyodide":
+        # there's only 1 possible configuration for pyodide, the single_python_tag one
+        expected_wheels = [
+            w.replace(f"{single_python_tag}-{single_python_tag}", f"{single_python_tag}-abi3")
+            for w in expected_wheels
+        ]
+    else:
+        expected_wheels = [
+            w.replace("cp310-cp310", "cp310-abi3")
+            for w in expected_wheels
+            if "-cp39" in w or "-cp310" in w or "-pp310" in w or "-cp313t" in w
+        ]
    assert set(actual_wheels) == set(expected_wheels)


@@ -155,6 +180,8 @@ ctypes_project.files["test/add_test.py"] = textwrap.dedent(
    """
 )

+ctypes_project.files["pyproject.toml"] = pyproject_toml
+

 def test_abi_none(tmp_path, capfd):
    project_dir = tmp_path / "project"
@@ -165,9 +192,9 @@ def test_abi_none(tmp_path, capfd):
        project_dir,
        add_env={
            "CIBW_TEST_REQUIRES": "pytest",
-            "CIBW_TEST_COMMAND": "pytest {project}/test",
+            "CIBW_TEST_COMMAND": f"{utils.invoke_pytest()} {{project}}/test",
            # limit the number of builds for test performance reasons
-            "CIBW_BUILD": "cp38-* cp310-* pp39-*",
+            "CIBW_BUILD": "cp38-* cp{}{}-* cp313t-* pp310-*".format(*utils.SINGLE_PYTHON_VERSION),
        },
    )

@@ -178,4 +205,8 @@ def test_abi_none(tmp_path, capfd):
    # check that each wheel was built once, and reused
    captured = capfd.readouterr()
    assert "Building wheel..." in captured.out
-    assert "Found previously built wheel" in captured.out
+    if utils.platform == "pyodide":
+        # there's only 1 possible configuration for pyodide, we won't see the message expected on following builds
+        assert "Found previously built wheel" not in captured.out
+    else:
+        assert "Found previously built wheel" in captured.out
@@ -10,13 +10,22 @@ from . import test_projects, utils
 project_with_before_build_asserts = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(
        r"""
-        # assert that the Python version as written to text_info.txt in the CIBW_BEFORE_ALL step
-        # is the same one as is currently running.
+        import os
+
        with open("text_info.txt") as f:
            stored_text = f.read()
-
        print("## stored text: " + stored_text)
        assert stored_text == "sample text 123"
+
+        # assert that the Python version as written to python_prefix.txt in the CIBW_BEFORE_ALL step
+        # is not the same one as is currently running.
+        with open('python_prefix.txt') as f:
+            stored_prefix = f.read()
+        print('stored_prefix', stored_prefix)
+        print('sys.prefix', sys.prefix)
+        #  Works around path-comparison bugs caused by short-paths on Windows e.g.
+        #  vssadm~1 instead of vssadministrator
+        assert not os.path.samefile(stored_prefix, sys.prefix)
        """
    )
 )
@@ -30,21 +39,24 @@ def test(tmp_path):
        print("dummy text", file=ff)

    # build the wheels
-    before_all_command = '''python -c "import os;open('{project}/text_info.txt', 'w').write('sample text '+os.environ.get('TEST_VAL', ''))"'''
+    before_all_command = (
+        """python -c "import os, sys;open('{project}/text_info.txt', 'w').write('sample text '+os.environ.get('TEST_VAL', ''))" && """
+        '''python -c "import sys; open('{project}/python_prefix.txt', 'w').write(sys.prefix)"'''
+    )
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
            # write python version information to a temporary file, this is
            # checked in setup.py
            "CIBW_BEFORE_ALL": before_all_command,
-            "CIBW_BEFORE_ALL_LINUX": f'{before_all_command} && python -c "import sys; assert sys.version_info >= (3, 6)"',
+            "CIBW_BEFORE_ALL_LINUX": f'{before_all_command} && python -c "import sys; assert sys.version_info >= (3, 8)"',
            "CIBW_ENVIRONMENT": "TEST_VAL='123'",
        },
+        single_python=True,
    )

    # also check that we got the right wheels
-    (project_dir / "text_info.txt").unlink()
-    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)


@@ -72,7 +84,8 @@ def test_cwd(tmp_path):
            "CIBW_BEFORE_ALL": f'''python -c "import os; assert os.getcwd() == {str(project_dir)!r}"''',
            "CIBW_BEFORE_ALL_LINUX": '''python -c "import os; assert os.getcwd() == '/project'"''',
        },
+        single_python=True,
    )

-    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)
@@ -7,33 +7,32 @@ import pytest

 from . import test_projects, utils

+# pyodide does not support building without isolation, need to check the base_prefix
+SYS_PREFIX = f"sys.{'base_' if utils.platform == 'pyodide' else ''}prefix"
+
+
 project_with_before_build_asserts = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(
-        r"""
+        rf"""
        import os

        # assert that the Python version as written to pythonversion_bb.txt in the CIBW_BEFORE_BUILD step
        # is the same one as is currently running.
-        version_file = 'c:\\pythonversion_bb.txt' if sys.platform == 'win32' else '/tmp/pythonversion_bb.txt'
-        with open(version_file) as f:
+        with open('pythonversion_bb.txt') as f:
            stored_version = f.read()
        print('stored_version', stored_version)
        print('sys.version', sys.version)
        assert stored_version == sys.version

-        # check that the executable also was written
-        executable_file = 'c:\\pythonexecutable_bb.txt' if sys.platform == 'win32' else '/tmp/pythonexecutable_bb.txt'
-        with open(executable_file) as f:
-            stored_executable = f.read()
-        print('stored_executable', stored_executable)
-        print('sys.executable', sys.executable)
+        # check that the prefix also was written
+        with open('pythonprefix_bb.txt') as f:
+            stored_prefix = f.read()
+        print('stored_prefix', stored_prefix)
+        print('{SYS_PREFIX}', {SYS_PREFIX})
+        #  Works around path-comparison bugs caused by short-paths on Windows e.g.
+        #  vssadm~1 instead of vssadministrator

-        # windows/mac are case insensitive
-        stored_path = os.path.realpath(stored_executable).lower()
-        current_path = os.path.realpath(sys.executable).lower()
-
-        # TODO: This is not valid in an virtual environment
-        assert stored_path == current_path, '{0} != {1}'.format(stored_path, current_path)
+        assert os.path.samefile(stored_prefix, {SYS_PREFIX})
        """
    )
 )
@@ -44,8 +43,8 @@ def test(tmp_path):
    project_with_before_build_asserts.generate(project_dir)

    before_build = (
-        """python -c "import sys; open('{output_dir}pythonversion_bb.txt', 'w').write(sys.version)" && """
-        '''python -c "import sys; open('{output_dir}pythonexecutable_bb.txt', 'w').write(sys.executable)"'''
+        """python -c "import sys; open('{project}/pythonversion_bb.txt', 'w').write(sys.version)" && """
+        f'''python -c "import sys; open('{{project}}/pythonprefix_bb.txt', 'w').write({SYS_PREFIX})"'''
    )

    # build the wheels
@@ -54,8 +53,7 @@ def test(tmp_path):
        add_env={
            # write python version information to a temporary file, this is
            # checked in setup.py
-            "CIBW_BEFORE_BUILD": before_build.format(output_dir="/tmp/"),
-            "CIBW_BEFORE_BUILD_WINDOWS": before_build.format(output_dir=r"c:\\"),
+            "CIBW_BEFORE_BUILD": before_build,
        },
    )

@@ -88,7 +86,8 @@ def test_cwd(tmp_path):
            "CIBW_BEFORE_BUILD": f'''python -c "import os; assert os.getcwd() == {str(project_dir)!r}"''',
            "CIBW_BEFORE_BUILD_LINUX": '''python -c "import os; assert os.getcwd() == '/project'"''',
        },
+        single_python=True,
    )

-    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)
@@ -6,32 +6,31 @@ before_test_project = test_projects.new_c_project()
 before_test_project.files["test/spam_test.py"] = r"""
 import sys
 import os
+from pathlib import Path
 from unittest import TestCase

+PROJECT_DIR = Path(__file__).joinpath("..", "..").resolve()
+

 class TestBeforeTest(TestCase):
    def test_version(self):
        # assert that the Python version as written to pythonversion_bt.txt in the CIBW_BEFORE_TEST step
        # is the same one as is currently running.
        # because of use symlinks in MacOS run this test is also need
-        version_file = 'c:\\pythonversion_bt.txt' if sys.platform == 'win32' else '/tmp/pythonversion_bt.txt'
-        with open(version_file) as f:
-            stored_version = f.read()
+        stored_version = PROJECT_DIR.joinpath('pythonversion_bt.txt').read_text()
        print('stored_version', stored_version)
        print('sys.version', sys.version)
        assert stored_version == sys.version

    def test_prefix(self):
        # check that the prefix also was written
-        prefix_file = 'c:\\pythonprefix_bt.txt' if sys.platform == 'win32' else '/tmp/pythonprefix_bt.txt'
-        with open(prefix_file) as f:
-            stored_prefix = f.read()
+        stored_prefix = PROJECT_DIR.joinpath('pythonprefix_bt.txt').read_text()
        print('stored_prefix', stored_prefix)
        print('sys.prefix', sys.prefix)
        #  Works around path-comparison bugs caused by short-paths on Windows e.g.
        #  vssadm~1 instead of vssadministrator

-        assert os.stat(stored_prefix) == os.stat(sys.prefix)
+        assert os.path.samefile(stored_prefix, sys.prefix)
 """


@@ -41,18 +40,31 @@ def test(tmp_path):
    test_project_dir = project_dir / "dependency"
    test_projects.new_c_project().generate(test_project_dir)

+    before_test_steps = [
+        '''python -c "import os, sys; open('{project}/pythonversion_bt.txt', 'w').write(sys.version)"''',
+        '''python -c "import os, sys; open('{project}/pythonprefix_bt.txt', 'w').write(sys.prefix)"''',
+    ]
+
+    if utils.platform == "pyodide":
+        before_test_steps.extend(
+            ["pyodide build {project}/dependency", "pip install --find-links dist/ spam"]
+        )
+    else:
+        before_test_steps.append("python -m pip install {project}/dependency")
+
+    before_test = " && ".join(before_test_steps)
+
    # build the wheels
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
            # write python version information to a temporary file, this is
            # checked in setup.py
-            "CIBW_BEFORE_TEST": """python -c "import sys; open('/tmp/pythonversion_bt.txt', 'w').write(sys.version)" && python -c "import sys; open('/tmp/pythonprefix_bt.txt', 'w').write(sys.prefix)" && python -m pip install {project}/dependency""",
-            "CIBW_BEFORE_TEST_WINDOWS": """python -c "import sys; open('c:\\pythonversion_bt.txt', 'w').write(sys.version)" && python -c "import sys; open('c:\\pythonprefix_bt.txt', 'w').write(sys.prefix)" && python -m pip install {project}/dependency""",
+            "CIBW_BEFORE_TEST": before_test,
            "CIBW_TEST_REQUIRES": "pytest",
            # the 'false ||' bit is to ensure this command runs in a shell on
            # mac/linux.
-            "CIBW_TEST_COMMAND": "false || pytest {project}/test",
+            "CIBW_TEST_COMMAND": f"false || {utils.invoke_pytest()} {{project}}/test",
            "CIBW_TEST_COMMAND_WINDOWS": "pytest {project}/test",
        },
    )
@@ -6,21 +6,24 @@ from . import utils
 from .test_projects.c import new_c_project


-@pytest.mark.parametrize("frontend_name", ["pip", "build"])
+@pytest.mark.parametrize(
+    "frontend_name",
+    [
+        pytest.param("pip", marks=utils.skip_if_pyodide("No pip for pyodide")),
+        "build",
+    ],
+)
 def test_build_frontend_args(tmp_path, capfd, frontend_name):
    project = new_c_project()
    project_dir = tmp_path / "project"
    project.generate(project_dir)

    # the build will fail because the frontend is called with '-h' - it prints the help message
+    add_env = {"CIBW_BUILD_FRONTEND": f"{frontend_name}; args: -h"}
+    if utils.platform == "pyodide":
+        add_env["TERM"] = "dumb"  # disable color / style
    with pytest.raises(subprocess.CalledProcessError):
-        utils.cibuildwheel_run(
-            project_dir,
-            add_env={
-                "CIBW_BUILD": "cp311-*",
-                "CIBW_BUILD_FRONTEND": f"{frontend_name}; args: -h",
-            },
-        )
+        utils.cibuildwheel_run(project_dir, add_env=add_env, single_python=True)

    captured = capfd.readouterr()
    print(captured.out)
@@ -29,6 +32,8 @@ def test_build_frontend_args(tmp_path, capfd, frontend_name):
    if frontend_name == "pip":
        assert "Usage:" in captured.out
        assert "Wheel Options:" in captured.out
+    elif utils.platform == "pyodide":
+        assert "Usage: pyodide build" in captured.out
    else:
        assert "usage:" in captured.out
        assert "A simple, correct Python build frontend." in captured.out
@@ -6,12 +6,12 @@ from . import test_projects, utils

 project_with_skip_asserts = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(
-        r"""
-        # explode if run on PyPyor Python 3.7 (these should be skipped)
+        rf"""
        if sys.implementation.name != "cpython":
            raise Exception("Only CPython shall be built")
-        if sys.version_info[0:2] == (3, 7):
-            raise Exception("CPython 3.7 should be skipped")
+        expected_version = {"({}, {})".format(*utils.SINGLE_PYTHON_VERSION)}
+        if sys.version_info[0:2] != expected_version:
+            raise Exception("CPython {{}}.{{}} should be skipped".format(*sys.version_info[0:2]))
        """
    )
 )
@@ -21,17 +21,19 @@ def test(tmp_path):
    project_dir = tmp_path / "project"
    project_with_skip_asserts.generate(project_dir)

+    skip = " ".join(
+        f"cp3{minor}-*" for minor in range(6, 30) if (3, minor) != utils.SINGLE_PYTHON_VERSION
+    )
+
    # build the wheels
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
            "CIBW_BUILD": "cp3*-*",
-            "CIBW_SKIP": "cp37-*",
+            "CIBW_SKIP": f"*t-* {skip}",
        },
    )

-    # check that we got the right wheels. There should be no PyPy or 3.7.
-    expected_wheels = [
-        w for w in utils.expected_wheels("spam", "0.1.0") if ("-cp3" in w) and ("-cp37" not in w)
-    ]
+    # check that we got the right wheels. There should be a single version of CPython.
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)
@@ -21,17 +21,16 @@ def test_podman(tmp_path, capfd, request):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp310-*{manylinux,musllinux}_x86_64",
+            "CIBW_ARCHS": "x86_64",
            "CIBW_BEFORE_ALL": "echo 'test log statement from before-all'",
            "CIBW_CONTAINER_ENGINE": "podman",
        },
+        single_python=True,
    )

    # check that the expected wheels are produced
    expected_wheels = [
-        w
-        for w in utils.expected_wheels("spam", "0.1.0")
-        if ("-cp310-" in w) and ("x86_64" in w) and ("manylinux" in w or "musllinux" in w)
+        w for w in utils.expected_wheels("spam", "0.1.0", single_python=True) if "x86_64" in w
    ]
    assert set(actual_wheels) == set(expected_wheels)

@@ -51,15 +50,16 @@ def test_create_args(tmp_path, capfd):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp310-manylinux_*",
+            "CIBW_SKIP": "*-musllinux_*",
            "CIBW_BEFORE_ALL": "echo TEST_CREATE_ARGS is set to $TEST_CREATE_ARGS",
            "CIBW_CONTAINER_ENGINE": "docker; create_args: --env=TEST_CREATE_ARGS=itworks",
        },
+        single_python=True,
    )

-    expected_wheels = [
-        w for w in utils.expected_wheels("spam", "0.1.0") if ("cp310-manylinux" in w)
-    ]
+    expected_wheels = utils.expected_wheels(
+        "spam", "0.1.0", musllinux_versions=[], single_python=True
+    )
    assert set(actual_wheels) == set(expected_wheels)

    captured = capfd.readouterr()
@@ -56,76 +56,62 @@ PyMODINIT_FUNC PyInit_spam(void)
 cpp_test_project.files["setup.py"] = jinja2.Template(setup_py_template)
 cpp_test_project.files["spam.cpp"] = jinja2.Template(spam_cpp_template)

-cpp11_project = cpp_test_project.copy()
-cpp11_project.template_context["extra_compile_args"] = (
-    ["/std:c++11"] if utils.platform == "windows" else ["-std=c++11"]
-)
-cpp11_project.template_context["spam_cpp_top_level_add"] = "#include <array>"
-

 def test_cpp11(tmp_path):
    # This test checks that the C++11 standard is supported
    project_dir = tmp_path / "project"
-
+    cpp11_project = cpp_test_project.copy()
+    cpp11_project.template_context["extra_compile_args"] = (
+        ["/std:c++11"] if utils.platform == "windows" else ["-std=c++11"]
+    )
+    cpp11_project.template_context["spam_cpp_top_level_add"] = "#include <array>"
    cpp11_project.generate(project_dir)

-    actual_wheels = utils.cibuildwheel_run(project_dir)
-    expected_wheels = list(utils.expected_wheels("spam", "0.1.0"))
+    actual_wheels = utils.cibuildwheel_run(project_dir, single_python=True)
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)

    assert set(actual_wheels) == set(expected_wheels)


-cpp14_project = cpp_test_project.copy()
-cpp14_project.template_context["extra_compile_args"] = (
-    ["/std:c++14"] if utils.platform == "windows" else ["-std=c++14"]
-)
-cpp14_project.template_context["spam_cpp_top_level_add"] = "int a = 100'000;"
-
-
 def test_cpp14(tmp_path):
    # This test checks that the C++14 standard is supported
    project_dir = tmp_path / "project"
-
+    cpp14_project = cpp_test_project.copy()
+    cpp14_project.template_context["extra_compile_args"] = (
+        ["/std:c++14"] if utils.platform == "windows" else ["-std=c++14"]
+    )
+    cpp14_project.template_context["spam_cpp_top_level_add"] = "int a = 100'000;"
    cpp14_project.generate(project_dir)

-    actual_wheels = utils.cibuildwheel_run(project_dir)
-    expected_wheels = list(utils.expected_wheels("spam", "0.1.0"))
+    actual_wheels = utils.cibuildwheel_run(project_dir, single_python=True)
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)

    assert set(actual_wheels) == set(expected_wheels)


-cpp17_project = cpp_test_project.copy()
-
-cpp17_project.template_context["extra_compile_args"] = [
-    "/std:c++17" if utils.platform == "windows" else "-std=c++17"
-]
-cpp17_project.template_context["spam_cpp_top_level_add"] = r"""
-#include <utility>
-auto a = std::pair(5.0, false);
-"""
-
-
 def test_cpp17(tmp_path):
    # This test checks that the C++17 standard is supported
    project_dir = tmp_path / "project"
-
+    cpp17_project = cpp_test_project.copy()
+    cpp17_project.template_context["extra_compile_args"] = [
+        "/std:c++17" if utils.platform == "windows" else "-std=c++17"
+    ]
+    cpp17_project.template_context["spam_cpp_top_level_add"] = r"""
+    #include <utility>
+    auto a = std::pair(5.0, false);
+    """
    cpp17_project.generate(project_dir)

    if os.environ.get("APPVEYOR_BUILD_WORKER_IMAGE", "") == "Visual Studio 2015":
        pytest.skip("Visual Studio 2015 does not support C++17")

-    # Pypy's distutils sets the default compiler to 'msvc9compiler', which
-    # is too old to support cpp17.
-    add_env = {"CIBW_SKIP": "pp*"}
-
+    add_env = {}
    if utils.platform == "macos":
        add_env["MACOSX_DEPLOYMENT_TARGET"] = "10.13"

-    actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env)
-    expected_wheels = [
-        w
-        for w in utils.expected_wheels("spam", "0.1.0", macosx_deployment_target="10.13")
-        if "-pp" not in w
-    ]
+    actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env, single_python=True)
+    expected_wheels = utils.expected_wheels(
+        "spam", "0.1.0", macosx_deployment_target="10.13", single_python=True
+    )

    assert set(actual_wheels) == set(expected_wheels)
@@ -1,10 +1,12 @@
 from __future__ import annotations

 import subprocess
-from test import test_projects
+from contextlib import nullcontext as does_not_raise

 import pytest

+from test import test_projects
+
 from . import utils

 basic_project = test_projects.new_c_project()
@@ -30,8 +32,14 @@ def test(tmp_path, capfd):
    project_dir = tmp_path / "project"
    basic_project.generate(project_dir)

-    with pytest.raises(subprocess.CalledProcessError):
-        utils.cibuildwheel_run(
+    num_builds = len(utils.cibuildwheel_get_build_identifiers(project_dir))
+    if num_builds > 1:
+        expectation = pytest.raises(subprocess.CalledProcessError)
+    else:
+        expectation = does_not_raise()
+
+    with expectation:
+        result = utils.cibuildwheel_run(
            project_dir,
            add_env={
                "CIBW_REPAIR_WHEEL_COMMAND": "python repair.py {wheel} {dest_dir}",
@@ -39,4 +47,14 @@ def test(tmp_path, capfd):
        )

    captured = capfd.readouterr()
-    assert "Build failed because a wheel named" in captured.err
+    if num_builds > 1:
+        assert "Build failed because a wheel named" in captured.err
+    else:
+        # We only produced one wheel (currently Pyodide)
+        # check that it has the right name
+        #
+        # As far as I can tell, this is the only full test coverage for
+        # CIBW_REPAIR_WHEEL_COMMAND so this is useful even in the case when no
+        # error is raised
+        assert "spam-0.1.0-py2-none-pyodide" in captured.out
+        assert result[0].startswith("spam-0.1.0-py2-none-")
@@ -15,9 +15,10 @@ project_with_expected_version_checks = test_projects.new_c_project(
        r"""
        import subprocess
        import os
+        import sys

        versions_output_text = subprocess.check_output(
-            ['pip', 'freeze', '--all', '-qq'],
+            [sys.executable, '-m', 'pip', 'freeze', '--all', '-qq'],
            universal_newlines=True,
        )
        versions = versions_output_text.strip().splitlines()
@@ -36,6 +37,11 @@ project_with_expected_version_checks = test_projects.new_c_project(
    )
 )

+project_with_expected_version_checks.files["pyproject.toml"] = r"""
+[build-system]
+requires = ["setuptools", "pip"]
+build-backend = "setuptools.build_meta"
+"""

 VERSION_REGEX = r"([\w-]+)==([^\s]+)"

@@ -47,30 +53,19 @@ def get_versions_from_constraint_file(constraint_file):


@pytest.mark.parametrize("python_version", ["3.6", "3.8", "3.10"])
-def test_pinned_versions(tmp_path, python_version, build_frontend_env):
+def test_pinned_versions(tmp_path, python_version, build_frontend_env_nouv):
    if utils.platform == "linux":
        pytest.skip("linux doesn't pin individual tool versions, it pins manylinux images instead")
+    if python_version == "3.6" and utils.platform == "macos" and platform.machine() == "arm64":
+        pytest.skip("macOS arm64 does not support Python 3.6")

    project_dir = tmp_path / "project"
    project_with_expected_version_checks.generate(project_dir)

+    version_no_dot = python_version.replace(".", "")
    build_environment = {}
-
-    if python_version == "3.6":
-        if utils.platform == "macos" and platform.machine() == "arm64":
-            pytest.skip("macOS arm64 does not support Python 3.6")
-        constraint_filename = "constraints-python36.txt"
-        build_pattern = "[cp]p36-*"
-    elif python_version == "3.7":
-        constraint_filename = "constraints-python37.txt"
-        build_pattern = "[cp]p37-*"
-    elif python_version == "3.8":
-        constraint_filename = "constraints-python38.txt"
-        build_pattern = "[cp]p38-*"
-    else:
-        constraint_filename = "constraints-python310.txt"
-        build_pattern = "[cp]p310-*"
-
+    build_pattern = f"[cp]p{version_no_dot}-*"
+    constraint_filename = f"constraints-python{version_no_dot}.txt"
    constraint_file = cibuildwheel.util.resources_dir / constraint_filename
    constraint_versions = get_versions_from_constraint_file(constraint_file)

@@ -84,31 +79,21 @@ def test_pinned_versions(tmp_path, python_version, build_frontend_env):
        add_env={
            "CIBW_BUILD": build_pattern,
            "CIBW_ENVIRONMENT": cibw_environment_option,
-            **build_frontend_env,
+            **build_frontend_env_nouv,
        },
    )

    # also check that we got the right wheels
-    if python_version == "3.6":
-        expected_wheels = [
-            w for w in utils.expected_wheels("spam", "0.1.0") if "-cp36" in w or "-pp36" in w
-        ]
-    elif python_version == "3.8":
-        expected_wheels = [
-            w for w in utils.expected_wheels("spam", "0.1.0") if "-cp38" in w or "-pp38" in w
-        ]
-    elif python_version == "3.10":
-        expected_wheels = [
-            w for w in utils.expected_wheels("spam", "0.1.0") if "-cp310" in w or "-pp310" in w
-        ]
-    else:
-        msg = "unhandled python version"
-        raise ValueError(msg)
+    expected_wheels = [
+        w
+        for w in utils.expected_wheels("spam", "0.1.0")
+        if f"-cp{version_no_dot}" in w or f"-pp{version_no_dot}" in w
+    ]

    assert set(actual_wheels) == set(expected_wheels)


-def test_dependency_constraints_file(tmp_path, build_frontend_env):
+def test_dependency_constraints_file(tmp_path, build_frontend_env_nouv):
    if utils.platform == "linux":
        pytest.skip("linux doesn't pin individual tool versions, it pins manylinux images instead")

@@ -126,7 +111,6 @@ def test_dependency_constraints_file(tmp_path, build_frontend_env):
            """
            pip=={pip}
            delocate=={delocate}
-            importlib-metadata<3,>=0.12; python_version < "3.8"
            """.format(**tool_versions)
        )
    )
@@ -146,7 +130,7 @@ def test_dependency_constraints_file(tmp_path, build_frontend_env):
            "CIBW_ENVIRONMENT": cibw_environment_option,
            "CIBW_DEPENDENCY_VERSIONS": str(constraints_file),
            "CIBW_SKIP": "cp36-*",
-            **build_frontend_env,
+            **build_frontend_env_nouv,
        },
    )

@@ -0,0 +1,84 @@
+from __future__ import annotations
+
+import shutil
+import sys
+import textwrap
+
+import pytest
+
+from cibuildwheel.util import CIBW_CACHE_PATH
+
+from . import test_projects, utils
+
+basic_project = test_projects.new_c_project()
+basic_project.files["check_node.py"] = r"""
+import sys
+import shutil
+from pathlib import Path
+from pyodide.code import run_js
+
+
+def check_node():
+    # cibuildwheel adds a pinned node version to the PATH
+    # check it's in the PATH then, check it's the one that runs pyoodide
+    cibw_cache_path = Path(sys.argv[1]).resolve(strict=True)
+    # find the node executable in PATH
+    node = shutil.which("node")
+    assert node is not None, "node is None"
+    node_path = Path(node).resolve(strict=True)
+    # it shall be in cibuildwheel cache
+    assert cibw_cache_path in node_path.parents, f"{cibw_cache_path} not a parent of {node_path}"
+    # find the path to the node executable that runs pyodide
+    node_js = run_js("globalThis.process.execPath")
+    assert node_js is not None, "node_js is None"
+    node_js_path = Path(node_js).resolve(strict=True)
+    # it shall be the one pinned by cibuildwheel
+    assert node_js_path == node_path, f"{node_js_path} != {node_path}"
+
+
+if __name__ == "__main__":
+    check_node()
+"""
+
+
+@pytest.mark.parametrize("use_pyproject_toml", [True, False])
+def test_pyodide_build(tmp_path, use_pyproject_toml):
+    if sys.platform == "win32":
+        pytest.skip("emsdk doesn't work correctly on Windows")
+
+    if not shutil.which("python3.12"):
+        pytest.skip("Python 3.12 not installed")
+
+    if use_pyproject_toml:
+        basic_project.files["pyproject.toml"] = textwrap.dedent(
+            """
+            [build-system]
+            requires = ["setuptools"]
+            build-backend = "setuptools.build_meta"
+            """
+        )
+
+    project_dir = tmp_path / "project"
+    basic_project.generate(project_dir)
+
+    # check for node in 1 case only to reduce CI load
+    add_env = {}
+    if use_pyproject_toml:
+        add_env["CIBW_TEST_COMMAND"] = f"python {{project}}/check_node.py {CIBW_CACHE_PATH}"
+
+    # build the wheels
+    actual_wheels = utils.cibuildwheel_run(
+        project_dir,
+        add_args=["--platform", "pyodide"],
+        add_env=add_env,
+    )
+
+    # check that the expected wheels are produced
+    expected_wheels = [
+        "spam-0.1.0-cp312-cp312-pyodide_2024_0_wasm32.whl",
+    ]
+
+    print("actual_wheels", actual_wheels)
+    print("expected_wheels", expected_wheels)
+
+    assert set(actual_wheels) == set(expected_wheels)
@@ -1,5 +1,6 @@
 from __future__ import annotations

+import itertools
 import subprocess

 import pytest
@@ -18,9 +19,13 @@ def test_spam():


 def test(tmp_path, request):
-    if not request.config.getoption("--run-emulation"):
+    archs = request.config.getoption("--run-emulation")
+    if archs is None:
        pytest.skip("needs --run-emulation option to run")

+    if archs == "all":
+        archs = " ".join(utils.EMULATED_ARCHS)
+
    project_dir = tmp_path / "project"
    project_with_a_test.generate(project_dir)

@@ -30,15 +35,14 @@ def test(tmp_path, request):
        add_env={
            "CIBW_TEST_REQUIRES": "pytest",
            "CIBW_TEST_COMMAND": "pytest {project}/test",
-            "CIBW_ARCHS": "aarch64 ppc64le s390x",
+            "CIBW_ARCHS": archs,
        },
    )

    # also check that we got the right wheels
-    expected_wheels = (
-        utils.expected_wheels("spam", "0.1.0", machine_arch="aarch64")
-        + utils.expected_wheels("spam", "0.1.0", machine_arch="ppc64le")
-        + utils.expected_wheels("spam", "0.1.0", machine_arch="s390x")
+    expected_wheels = itertools.chain.from_iterable(
+        utils.expected_wheels("spam", "0.1.0", machine_arch=arch, single_arch=True)
+        for arch in archs.split(" ")
    )
    assert set(actual_wheels) == set(expected_wheels)

@@ -49,10 +49,11 @@ def test(tmp_path):
            "CIBW_ENVIRONMENT": """CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$(echo 'test string 3')" PATH=$PATH:/opt/cibw_test_path""",
            "CIBW_ENVIRONMENT_WINDOWS": f'''CIBW_TEST_VAR="a b c" CIBW_TEST_VAR_2=1 CIBW_TEST_VAR_3="$({python_echo} 'test string 3')" PATH="$PATH;/opt/cibw_test_path"''',
        },
+        single_python=True,
    )

    # also check that we got the right wheels built
-    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)


@@ -92,10 +93,18 @@ def test_overridden_path(tmp_path, capfd):

    assert len(os.listdir(output_dir)) == 0
    captured = capfd.readouterr()
-    assert "python available on PATH doesn't match our installed instance" in captured.err
+    assert "python available on PATH doesn't match our installed instance" in captured.err.replace(
+        "venv", "installed"
+    )


-@pytest.mark.parametrize("build_frontend", ["pip", "build"])
+@pytest.mark.parametrize(
+    "build_frontend",
+    [
+        pytest.param("pip", marks=utils.skip_if_pyodide("No pip for pyodide")),
+        "build",
+    ],
+)
 def test_overridden_pip_constraint(tmp_path, build_frontend):
    """
    Verify that users can use PIP_CONSTRAINT to specify a specific version of
@@ -108,7 +117,7 @@ def test_overridden_pip_constraint(tmp_path, build_frontend):
        setup_py_add=textwrap.dedent(
            """
            import pytz
-            assert pytz.__version__ == "2022.4"
+            assert pytz.__version__ == "2022.4", f"{pytz.__version__!r} != '2022.4'"
        """
        )
    )
@@ -133,12 +142,12 @@ def test_overridden_pip_constraint(tmp_path, build_frontend):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp312-*",
            "CIBW_BUILD_FRONTEND": build_frontend,
            "PIP_CONSTRAINT": str(constraints_file),
            "CIBW_ENVIRONMENT_LINUX": "PIP_CONSTRAINT=./constraints.txt",
        },
+        single_python=True,
    )

-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp312" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)
@@ -6,6 +6,7 @@ import sys
 import textwrap
 from pathlib import Path
 from tempfile import TemporaryDirectory
+
 from test.test_projects.base import TestProject

 from . import test_projects, utils
@@ -33,6 +34,8 @@ def cibuildwheel_from_sdist_run(sdist_path, add_env=None, config_file=None):
    if add_env:
        env.update(add_env)

+    env["CIBW_BUILD"] = "cp{}{}-*".format(*utils.SINGLE_PYTHON_VERSION)
+
    with TemporaryDirectory() as tmp_output_dir:
        subprocess.run(
            [
@@ -73,15 +76,11 @@ def test_simple(tmp_path):

    # build the wheels from sdist
    actual_wheels = cibuildwheel_from_sdist_run(
-        sdist_path,
-        add_env={
-            "CIBW_BEFORE_BUILD": setup_py_assertion_cmd,
-            "CIBW_BUILD": "cp39-*",
-        },
+        sdist_path, add_env={"CIBW_BEFORE_BUILD": setup_py_assertion_cmd}
    )

    # check that the expected wheels are produced
-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp39" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)


@@ -105,14 +104,10 @@ def test_external_config_file_argument(tmp_path, capfd):
    )

    # build the wheels from sdist
-    actual_wheels = cibuildwheel_from_sdist_run(
-        sdist_path,
-        add_env={"CIBW_BUILD": "cp39-*"},
-        config_file=str(config_file),
-    )
+    actual_wheels = cibuildwheel_from_sdist_run(sdist_path, config_file=str(config_file))

    # check that the expected wheels are produced
-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp39" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)

    # check that before-all was run
@@ -136,13 +131,10 @@ def test_config_in_pyproject_toml(tmp_path, capfd):
    sdist_path = make_sdist(project, sdist_dir)

    # build the wheels from sdist
-    actual_wheels = cibuildwheel_from_sdist_run(
-        sdist_path,
-        add_env={"CIBW_BUILD": "cp39-*"},
-    )
+    actual_wheels = cibuildwheel_from_sdist_run(sdist_path)

    # check that the expected wheels are produced
-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp39" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)

    # check that before-build was run
@@ -174,13 +166,11 @@ def test_internal_config_file_argument(tmp_path, capfd):

    # build the wheels from sdist, referencing the config file inside
    actual_wheels = cibuildwheel_from_sdist_run(
-        sdist_path,
-        add_env={"CIBW_BUILD": "cp39-*"},
-        config_file="{package}/wheel_build_config.toml",
+        sdist_path, config_file="{package}/wheel_build_config.toml"
    )

    # check that the expected wheels are produced
-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp39" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)

    # check that before-all was run
@@ -14,7 +14,7 @@ ALL_MACOS_WHEELS = {
    *utils.expected_wheels("spam", "0.1.0", machine_arch="arm64", include_universal2=True),
 }

-DEPLOYMENT_TARGET_TOO_LOW_WARNING = "[WARNING] MACOSX_DEPLOYMENT_TARGET is set to a lower value"
+DEPLOYMENT_TARGET_TOO_LOW_WARNING = "Bumping MACOSX_DEPLOYMENT_TARGET"


 def get_xcode_version() -> tuple[int, int]:
@@ -42,13 +42,11 @@ def test_cross_compiled_build(tmp_path):

    actual_wheels = utils.cibuildwheel_run(
        project_dir,
-        add_env={
-            "CIBW_BUILD": "cp39-*",
-            "CIBW_ARCHS": "x86_64, universal2, arm64",
-        },
+        add_env={"CIBW_ARCHS": "x86_64, universal2, arm64"},
+        single_python=True,
    )
-
-    expected_wheels = [w for w in ALL_MACOS_WHEELS if "cp39" in w]
+    python_tag = "cp{}{}".format(*utils.SINGLE_PYTHON_VERSION)
+    expected_wheels = [w for w in ALL_MACOS_WHEELS if python_tag in w]
    assert set(actual_wheels) == set(expected_wheels)


@@ -65,7 +63,7 @@ def test_cross_compiled_test(tmp_path, capfd, build_universal2):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp39-*" if build_universal2 else "*p39-*",
+            "CIBW_BUILD": "cp310-*" if build_universal2 else "*p310-*",
            "CIBW_TEST_COMMAND": '''python -c "import platform; print('running tests on ' + platform.machine())"''',
            "CIBW_ARCHS": "universal2" if build_universal2 else "x86_64 arm64",
            "CIBW_BUILD_VERBOSITY": "3",
@@ -103,11 +101,11 @@ def test_cross_compiled_test(tmp_path, capfd, build_universal2):
        )

    if build_universal2:
-        expected_wheels = [w for w in ALL_MACOS_WHEELS if "cp39" in w and "universal2" in w]
+        expected_wheels = [w for w in ALL_MACOS_WHEELS if "cp310" in w and "universal2" in w]
    else:
-        expected_wheels = [w for w in ALL_MACOS_WHEELS if "p39-" in w and "universal2" not in w]
+        expected_wheels = [w for w in ALL_MACOS_WHEELS if "p310-" in w and "universal2" not in w]
        if platform_machine == "x86_64":
-            expected_wheels = [w for w in expected_wheels if not ("pp39" in w and "arm64" in w)]
+            expected_wheels = [w for w in expected_wheels if not ("pp310" in w and "arm64" in w)]

    assert set(actual_wheels) == set(expected_wheels)

@@ -123,11 +121,11 @@ def test_deployment_target_warning_is_firing(tmp_path, capfd):
    utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp39-*",
            "CIBW_ARCHS": "x86_64",
            "MACOSX_DEPLOYMENT_TARGET": "10.8",
            "CIBW_BUILD_VERBOSITY": "3",
        },
+        single_python=True,
    )

    captured = capfd.readouterr()
@@ -149,11 +147,11 @@ def test_universal2_testing_on_x86_64(tmp_path, capfd, skip_arm64_test):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp39-*",
            "CIBW_TEST_COMMAND": '''python -c "import platform; print('running tests on ' + platform.machine())"''',
            "CIBW_ARCHS": "universal2",
            "CIBW_TEST_SKIP": "*_universal2:arm64" if skip_arm64_test else "",
        },
+        single_python=True,
    )

    captured = capfd.readouterr()
@@ -168,12 +166,13 @@ def test_universal2_testing_on_x86_64(tmp_path, capfd, skip_arm64_test):
        else:
            assert warning_message in captured.err

-    expected_wheels = [w for w in ALL_MACOS_WHEELS if "cp39" in w and "universal2" in w]
+    python_tag = "cp{}{}".format(*utils.SINGLE_PYTHON_VERSION)
+    expected_wheels = [w for w in ALL_MACOS_WHEELS if python_tag in w and "universal2" in w]

    assert set(actual_wheels) == set(expected_wheels)


-def test_universal2_testing_on_arm64(tmp_path, capfd):
+def test_universal2_testing_on_arm64(build_frontend_env, tmp_path, capfd):
    # cibuildwheel should test the universal2 wheel on both x86_64 and arm64, when run on arm64
    if utils.platform != "macos":
        pytest.skip("this test is only relevant to macos")
@@ -186,29 +185,33 @@ def test_universal2_testing_on_arm64(tmp_path, capfd):
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
        add_env={
-            "CIBW_BUILD": "cp39-*",
            "CIBW_ARCHS": "universal2",
            # check that a native dependency is correctly installed, once per each testing arch
-            "CIBW_TEST_REQUIRES": "numpy",
-            "CIBW_TEST_COMMAND": '''python -c "import numpy, platform; print(f'running tests on {platform.machine()} with numpy {numpy.__version__}')"''',
+            "CIBW_TEST_REQUIRES": "--only-binary :all: pillow>=10.3",  # pillow>=10.3 provides wheels for macOS 10.10, not 10.9
+            "CIBW_TEST_COMMAND": '''python -c "import PIL, platform; print(f'running tests on {platform.machine()} with pillow {PIL.__version__}')"''',
+            **build_frontend_env,
        },
+        single_python=True,
    )

    captured = capfd.readouterr()
-    assert "running tests on arm64" in captured.out
-    assert "running tests on x86_64" in captured.out
+    assert "running tests on arm64 with pillow" in captured.out
+    assert "running tests on x86_64 with pillow" in captured.out

-    expected_wheels = [w for w in ALL_MACOS_WHEELS if "cp39" in w and "universal2" in w]
+    python_tag = "cp{}{}".format(*utils.SINGLE_PYTHON_VERSION)
+    expected_wheels = [w for w in ALL_MACOS_WHEELS if python_tag in w and "universal2" in w]
    assert set(actual_wheels) == set(expected_wheels)


-def test_cp38_arm64_testing(tmp_path, capfd):
+def test_cp38_arm64_testing(tmp_path, capfd, request):
    if utils.platform != "macos":
        pytest.skip("this test is only relevant to macos")
    if get_xcode_version() < (12, 2):
        pytest.skip("this test only works with Xcode 12.2 or greater")
    if platform.machine() != "arm64":
        pytest.skip("this test only works on arm64")
+    if request.config.getoption("--run-cp38-universal2"):
+        pytest.skip("--run-cp38-universal2 option skips this test")

    project_dir = tmp_path / "project"
    basic_project.generate(project_dir)
@@ -86,10 +86,10 @@ def test(manylinux_image, tmp_path):
        add_env["CIBW_SKIP"] = "pp* cp31*"
    if manylinux_image in {"manylinux2010"}:
        # We don't have a manylinux2010 image for PyPy 3.9+, CPython 3.11+
-        add_env["CIBW_SKIP"] = "pp39* pp31* cp311* cp312*"
+        add_env["CIBW_SKIP"] = "pp39* pp31* cp311* cp312* cp313*"
    if manylinux_image in {"manylinux_2_24"}:
        # We don't have a manylinux_2_24 image for PyPy 3.10+, CPython 3.12+
-        add_env["CIBW_SKIP"] = "pp31* cp312*"
+        add_env["CIBW_SKIP"] = "pp31* cp312* cp313*"
    if manylinux_image == "manylinux_2_28" and platform.machine() == "x86_64":
        # We don't have a manylinux_2_28 image for i686
        add_env["CIBW_ARCHS"] = "x86_64"
@@ -116,12 +116,20 @@ def test(manylinux_image, tmp_path):
        expected_wheels = [
            w
            for w in expected_wheels
-            if "-pp39" not in w and "-pp31" not in w and "-cp311" not in w and "-cp312" not in w
+            if "-pp39" not in w
+            and "-pp31" not in w
+            and "-cp311" not in w
+            and "-cp312" not in w
+            and "-cp313" not in w
        ]

    if manylinux_image in {"manylinux_2_24"}:
        # remove PyPy 3.10+ & CPython 3.11 and above
-        expected_wheels = [w for w in expected_wheels if "-pp31" not in w and "-cp312" not in w]
+        expected_wheels = [
+            w
+            for w in expected_wheels
+            if "-pp31" not in w and "-cp312" not in w and "-cp313" not in w
+        ]

    if manylinux_image == "manylinux_2_28" and platform.machine() == "x86_64":
        # We don't have a manylinux_2_28 image for i686
@@ -38,7 +38,7 @@ def test(musllinux_image, tmp_path):

    # build the wheels
    add_env = {
-        "CIBW_BUILD": "*-musllinux*",
+        "CIBW_SKIP": "*-manylinux*",
        "CIBW_MUSLLINUX_X86_64_IMAGE": musllinux_image,
        "CIBW_MUSLLINUX_I686_IMAGE": musllinux_image,
        "CIBW_MUSLLINUX_AARCH64_IMAGE": musllinux_image,
@@ -46,11 +46,12 @@ def test(musllinux_image, tmp_path):
        "CIBW_MUSLLINUX_S390X_IMAGE": musllinux_image,
    }

-    actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env)
+    actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env, single_python=True)
    expected_wheels = utils.expected_wheels(
        "spam",
        "0.1.0",
        manylinux_versions=[],
        musllinux_versions=[musllinux_image],
+        single_python=True,
    )
    assert set(actual_wheels) == set(expected_wheels)
@@ -42,15 +42,20 @@ PyMODINIT_FUNC PyInit_spam(void)
 """

 SETUP_PY_TEMPLATE = r"""
+import os
 import sys
+
 from setuptools import setup, Extension

 {{ setup_py_add }}

 libraries = []
-if sys.platform.startswith('linux'):
+# Emscripten fails if you pass -lc...
+# See: https://github.com/emscripten-core/emscripten/issues/16680
+if sys.platform.startswith('linux') and "emscripten" not in os.environ.get("_PYTHON_HOST_PLATFORM", ""):
    libraries.extend(['m', 'c'])

+
 setup(
    ext_modules=[Extension(
        'spam',
@@ -1,10 +1,11 @@
 from __future__ import annotations

 import subprocess
-from test import test_projects

 import pytest

+from test import test_projects
+
 from . import utils

 pure_python_project = test_projects.TestProject()
@@ -45,13 +45,12 @@ def test(capfd, tmp_path):
        add_env={
            "CIBW_BEFORE_BUILD": "python {project}/bin/before_build.py",
            "CIBW_TEST_COMMAND": "python {package}/test/run_tests.py",
-            # this shouldn't depend on the version of python, so build only CPython 3.10
-            "CIBW_BUILD": "cp310-*",
        },
+        single_python=True,
    )

    # check that the expected wheels are produced
-    expected_wheels = [w for w in utils.expected_wheels("spam", "0.1.0") if "cp310" in w]
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)

    captured = capfd.readouterr()
@@ -58,6 +58,7 @@ class TestSpam(TestCase):

        self.assertTrue(path_contains(sys.prefix, sys.executable))
        self.assertTrue(path_contains(sys.prefix, spam.__file__))
+        self.assertIn("VIRTUAL_ENV", os.environ)

    def test_uname(self):
        if platform.system() == "Windows":
@@ -66,7 +67,7 @@ class TestSpam(TestCase):
        # See #336 for more info.
        bits = struct.calcsize("P") * 8
        if bits == 32:
-            self.assertEqual(platform.machine(), "i686")
+            self.assertIn(platform.machine(), ["i686", "wasm32"])
 '''


@@ -81,7 +82,7 @@ def test(tmp_path):
            "CIBW_TEST_REQUIRES": "pytest",
            # the 'false ||' bit is to ensure this command runs in a shell on
            # mac/linux.
-            "CIBW_TEST_COMMAND": "false || pytest {project}/test",
+            "CIBW_TEST_COMMAND": f"false || {utils.invoke_pytest()} {{project}}/test",
            "CIBW_TEST_COMMAND_WINDOWS": "COLOR 00 || pytest {project}/test",
        },
    )
@@ -102,13 +103,14 @@ def test_extras_require(tmp_path):
            "CIBW_TEST_EXTRAS": "test",
            # the 'false ||' bit is to ensure this command runs in a shell on
            # mac/linux.
-            "CIBW_TEST_COMMAND": "false || pytest {project}/test",
+            "CIBW_TEST_COMMAND": f"false || {utils.invoke_pytest()} {{project}}/test",
            "CIBW_TEST_COMMAND_WINDOWS": "COLOR 00 || pytest {project}/test",
        },
+        single_python=True,
    )

    # also check that we got the right wheels
-    expected_wheels = utils.expected_wheels("spam", "0.1.0")
+    expected_wheels = utils.expected_wheels("spam", "0.1.0", single_python=True)
    assert set(actual_wheels) == set(expected_wheels)


@@ -18,17 +18,14 @@ def test_wheel_tag_is_correct_when_using_macosx_deployment_target(tmp_path):
    deployment_target = "10.11"
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
-        add_env={
-            "CIBW_BUILD": "cp39-*",
-            "MACOSX_DEPLOYMENT_TARGET": deployment_target,
-        },
+        add_env={"MACOSX_DEPLOYMENT_TARGET": deployment_target},
+        single_python=True,
    )

    # check that the expected wheels are produced
    expected_wheels = utils.expected_wheels(
-        "spam", "0.1.0", macosx_deployment_target=deployment_target
+        "spam", "0.1.0", macosx_deployment_target=deployment_target, single_python=True
    )
-    expected_wheels = [w for w in expected_wheels if "cp39" in w]

    print("actual_wheels", actual_wheels)
    print("expected_wheels", expected_wheels)
@@ -60,16 +60,13 @@ def test_wheel_tag_is_correct_when_using_windows_cross_compile(tmp_path, use_pyp
    # build the wheels
    actual_wheels = utils.cibuildwheel_run(
        project_dir,
-        add_env={
-            "CIBW_BUILD": "cp310-*",
-        },
        add_args=["--archs", "ARM64"],
+        single_python=True,
    )

    # check that the expected wheels are produced
-    expected_wheels = [
-        "spam-0.1.0-cp310-cp310-win_arm64.whl",
-    ]
+    tag = "cp{}{}".format(*utils.SINGLE_PYTHON_VERSION)
+    expected_wheels = [f"spam-0.1.0-{tag}-{tag}-win_arm64.whl"]

    print("actual_wheels", actual_wheels)
    print("expected_wheels", expected_wheels)
@@ -11,9 +11,18 @@ import platform as pm
 import subprocess
 import sys
 from tempfile import TemporaryDirectory
+from typing import Final

+import pytest
+
+from cibuildwheel.architecture import Architecture
 from cibuildwheel.util import CIBW_CACHE_PATH

+EMULATED_ARCHS: Final[list[str]] = sorted(
+    arch.value for arch in (Architecture.all_archs("linux") - Architecture.auto_archs("linux"))
+)
+SINGLE_PYTHON_VERSION: Final[tuple[int, int]] = (3, 12)
+
 platform: str

 if "CIBW_PLATFORM" in os.environ:
@@ -37,6 +46,9 @@ def cibuildwheel_get_build_identifiers(project_path, env=None, *, prerelease_pyt
    cmd = [sys.executable, "-m", "cibuildwheel", "--print-build-identifiers", str(project_path)]
    if prerelease_pythons:
        cmd.append("--prerelease-pythons")
+    if env is None:
+        env = os.environ.copy()
+    env.setdefault("CIBW_FREE_THREADED_SUPPORT", "1")

    cmd_output = subprocess.run(
        cmd,
@@ -64,7 +76,13 @@ def _update_pip_cache_dir(env: dict[str, str]) -> None:


 def cibuildwheel_run(
-    project_path, package_dir=".", env=None, add_env=None, output_dir=None, add_args=None
+    project_path,
+    package_dir=".",
+    env=None,
+    add_env=None,
+    output_dir=None,
+    add_args=None,
+    single_python=False,
 ):
    """
    Runs cibuildwheel as a subprocess, building the project at project_path.
@@ -94,6 +112,11 @@ def cibuildwheel_run(

    _update_pip_cache_dir(env)

+    env.setdefault("CIBW_FREE_THREADED_SUPPORT", "1")
+
+    if single_python:
+        env["CIBW_BUILD"] = "cp{}{}-*".format(*SINGLE_PYTHON_VERSION)
+
    with TemporaryDirectory() as tmp_output_dir:
        subprocess.run(
            [
@@ -114,17 +137,11 @@ def cibuildwheel_run(
    return wheels


-def _get_arm64_macosx_deployment_target(macosx_deployment_target: str) -> str:
+def _floor_macosx(*args: str) -> str:
    """
-    The first version of macOS that supports arm is 11.0. So the wheel tag
-    cannot contain an earlier deployment target, even if
-    MACOSX_DEPLOYMENT_TARGET sets it.
+    Make sure a deployment target is not less than some value.
    """
-    version_tuple = tuple(map(int, macosx_deployment_target.split(".")))
-    if version_tuple <= (11, 0):
-        return "11.0"
-    else:
-        return macosx_deployment_target
+    return max(args, key=lambda x: tuple(map(int, x.split("."))))


 def expected_wheels(
@@ -136,6 +153,8 @@ def expected_wheels(
    machine_arch=None,
    python_abi_tags=None,
    include_universal2=False,
+    single_python=False,
+    single_arch=False,
 ):
    """
    Returns a list of expected wheels from a run of cibuildwheel.
@@ -147,6 +166,9 @@ def expected_wheels(

    if machine_arch is None:
        machine_arch = pm.machine()
+        if platform == "linux" and machine_arch.lower() == "arm64":
+            # we're running linux tests from macOS/Windows arm64, override platform
+            machine_arch = "aarch64"

    if manylinux_versions is None:
        if machine_arch == "x86_64":
@@ -160,8 +182,10 @@ def expected_wheels(
            manylinux_versions = ["manylinux_2_17", "manylinux2014"]

    if musllinux_versions is None:
-        musllinux_versions = ["musllinux_1_1"]
+        musllinux_versions = ["musllinux_1_2"]

+    if platform == "pyodide" and python_abi_tags is None:
+        python_abi_tags = ["cp312-cp312"]
    if python_abi_tags is None:
        python_abi_tags = [
            "cp36-cp36m",
@@ -171,6 +195,8 @@ def expected_wheels(
            "cp310-cp310",
            "cp311-cp311",
            "cp312-cp312",
+            "cp313-cp313",
+            "cp313-cp313t",
        ]

        if machine_arch in ["x86_64", "AMD64", "x86", "aarch64"]:
@@ -189,20 +215,38 @@ def expected_wheels(
                "cp310-cp310",
                "cp311-cp311",
                "cp312-cp312",
+                "cp313-cp313",
+                "cp313-cp313t",
                "pp38-pypy38_pp73",
                "pp39-pypy39_pp73",
                "pp310-pypy310_pp73",
            ]

+    if single_python:
+        python_tag = "cp{}{}-".format(*SINGLE_PYTHON_VERSION)
+        python_abi_tags = [
+            next(
+                tag
+                for tag in python_abi_tags
+                if tag.startswith(python_tag) and not tag.endswith("t")
+            )
+        ]
+
    wheels = []

+    if platform == "pyodide":
+        assert len(python_abi_tags) == 1
+        python_abi_tag = python_abi_tags[0]
+        platform_tag = "pyodide_2024_0_wasm32"
+        return [f"{package_name}-{package_version}-{python_abi_tag}-{platform_tag}.whl"]
+
    for python_abi_tag in python_abi_tags:
        platform_tags = []

        if platform == "linux":
            architectures = [arch_name_for_linux(machine_arch)]

-            if machine_arch == "x86_64":
+            if machine_arch == "x86_64" and not single_arch:
                architectures.append("i686")

            if len(manylinux_versions) > 0:
@@ -232,18 +276,24 @@ def expected_wheels(

        elif platform == "macos":
            if machine_arch == "arm64":
-                arm64_macosx_deployment_target = _get_arm64_macosx_deployment_target(
-                    macosx_deployment_target
-                )
-                platform_tags = [f'macosx_{arm64_macosx_deployment_target.replace(".", "_")}_arm64']
+                arm64_macosx = _floor_macosx(macosx_deployment_target, "11.0")
+                platform_tags = [f'macosx_{arm64_macosx.replace(".", "_")}_arm64']
            else:
-                platform_tags = [f'macosx_{macosx_deployment_target.replace(".", "_")}_x86_64']
+                if python_abi_tag.startswith("pp") and not python_abi_tag.startswith(
+                    ("pp37", "pp38")
+                ):
+                    pypy_macosx = _floor_macosx(macosx_deployment_target, "10.15")
+                    platform_tags = [f'macosx_{pypy_macosx.replace(".", "_")}_x86_64']
+                elif python_abi_tag.startswith("cp313"):
+                    pypy_macosx = _floor_macosx(macosx_deployment_target, "10.13")
+                    platform_tags = [f'macosx_{pypy_macosx.replace(".", "_")}_x86_64']
+                else:
+                    platform_tags = [f'macosx_{macosx_deployment_target.replace(".", "_")}_x86_64']

            if include_universal2:
                platform_tags.append(
                    f'macosx_{macosx_deployment_target.replace(".", "_")}_universal2',
                )
-
        else:
            msg = f"Unsupported platform {platform!r}"
            raise Exception(msg)
@@ -266,6 +316,17 @@ def get_macos_version():
    return tuple(map(int, version_str.split(".")[:2]))


+def skip_if_pyodide(reason: str):
+    return pytest.mark.skipif(platform == "pyodide", reason=reason)
+
+
+def invoke_pytest() -> str:
+    # see https://github.com/pyodide/pyodide/issues/4802
+    if platform == "pyodide" and sys.platform.startswith("darwin"):
+        return "python -m pytest"
+    return "pytest"
+
+
 def arch_name_for_linux(arch: str):
    """
    Archs have different names on different platforms, but it's useful to be
@@ -13,6 +13,7 @@ def test_build():
    assert build_selector("cp310-manylinux_x86_64")
    assert build_selector("cp311-manylinux_x86_64")
    assert build_selector("cp312-manylinux_x86_64")
+    assert not build_selector("cp313-manylinux_x86_64")
    assert build_selector("pp36-manylinux_x86_64")
    assert build_selector("pp37-manylinux_x86_64")
    assert build_selector("cp36-manylinux_i686")
@@ -33,6 +34,7 @@ def test_build():
    assert build_selector("cp310-win_amd64")
    assert build_selector("cp311-win_amd64")
    assert build_selector("cp312-win_amd64")
+    assert not build_selector("cp313-win_amd64")
    assert not build_selector("pp36-win_amd64")
    assert not build_selector("pp37-win_amd64")

@@ -45,9 +47,10 @@ def test_build_filter_pre():
    )

    assert build_selector("cp37-manylinux_x86_64")
-    assert build_selector("cp312-manylinux_x86_64")
+    assert build_selector("cp313-manylinux_x86_64")
    assert build_selector("cp37-win_amd64")
-    assert build_selector("cp312-win_amd64")
+    assert build_selector("cp313-win_amd64")
+    assert not build_selector("cp313t-manylinux_x86_64")


 def test_skip():
@@ -142,6 +145,14 @@ def test_build_limited_python_patch():
    assert build_selector("cp37-manylinux_x86_64")


+def test_build_free_threaded_python():
+    build_selector = BuildSelector(
+        build_config="*", skip_config="", prerelease_pythons=True, free_threaded_support=True
+    )
+
+    assert build_selector("cp313t-manylinux_x86_64")
+
+
 def test_testing_selector():
    # local import to avoid pytest trying to collect this as a test class!
    from cibuildwheel.util import TestSelector
--- a/Show More
+++ b/Show More