Bump version: v2.19.1

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>

.github/workflows/test.yml

@@ -31,7 +31,7 @@ jobs:
       run: pipx run nox -s pylint -- --output-format=github
 
   test:
-    name: Test cibuildwheel on ${{ matrix.os }} (${{ matrix.python_version }})
+    name: Test on ${{ matrix.os }} (${{ matrix.python_version }})
     needs: lint
     runs-on: ${{ matrix.os }}
     strategy:
@@ -49,6 +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
@@ -69,7 +71,7 @@ jobs:
 
     - name: Install dependencies
       run: |
-        python -m pip install ".[test]"
+        uv pip install --system ".[test]"
 
     - name: Generate a sample project
       run: |
@@ -82,6 +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: ./
@@ -125,19 +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
@@ -146,5 +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

.pre-commit-config.yaml

@@ -14,7 +14,7 @@ repos:
   - id: trailing-whitespace
 
 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: v0.4.4
+  rev: v0.4.8
   hooks:
   - id: ruff
     args: ["--fix", "--show-fixes"]
@@ -40,6 +40,7 @@ repos:
       - types-jinja2
       - types-pyyaml
       - types-requests
+      - uv
       - validate-pyproject
   - id: mypy
     name: mypy 3.12
@@ -68,15 +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: 0.28.3
+  rev: 0.28.4
   hooks:
     - id: check-dependabot
     - id: check-github-actions

README.md

@@ -22,24 +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 | ✅ | ✅  | ✅ | ✅  | ✅  |
-| CPython 3.13³  | ✅ | ✅  | ✅  | ✅  | ✅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.</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
@@ -93,7 +94,7 @@ jobs:
       - uses: actions/setup-python@v5
 
       - name: Install cibuildwheel
-        run: python -m pip install cibuildwheel==2.18.1
+        run: python -m pip install cibuildwheel==2.19.1
 
       - name: Build wheels
         run: python -m cibuildwheel --output-dir wheelhouse
@@ -163,9 +164,9 @@ 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. |
-| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an in-process SQL OLAP Database Management System |
 | [Kivy][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Open source UI framework written in Python, running on Windows, Linux, macOS, Android and iOS |
 
 [scikit-learn]: https://github.com/scikit-learn/scikit-learn
@@ -174,9 +175,9 @@ Here are some repos that use cibuildwheel.
 [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
-[duckdb]: https://github.com/duckdb/duckdb
 [Kivy]: https://github.com/kivy/kivy
 
 [appveyor icon]: docs/data/readme_icons/appveyor.svg
@@ -210,6 +211,33 @@ 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)
@@ -256,20 +284,6 @@ _11 March 2024_
 - 📚 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)
-
 <!-- END bin/update_readme_changelog.py -->
 
 ---

action.yml

@@ -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

bin/generate_schema.py

@@ -48,19 +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:
@@ -280,6 +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"] = {

bin/update_nodejs.py

@@ -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()

cibuildwheel/__init__.py

@@ -1,3 +1,3 @@
 from __future__ import annotations
 
-__version__ = "2.18.1"
+__version__ = "2.19.1"

cibuildwheel/__main__.py

@@ -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)
@@ -246,11 +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
@@ -258,9 +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(
@@ -291,16 +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
 
@@ -355,7 +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]

cibuildwheel/architecture.py

@@ -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]
 

cibuildwheel/errors.py

@@ -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

cibuildwheel/linux.py

@@ -8,6 +8,9 @@ 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
@@ -145,11 +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(
@@ -194,6 +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] = []
 
@@ -221,19 +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:
@@ -277,10 +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",
@@ -325,20 +328,32 @@ 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":
+            if config.version == "3.13" and not use_uv:
                 container.call(["pip", "install", "pip>=24.1b1"], env=virtualenv_env)
 
             if build_options.before_test:
@@ -357,13 +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(
@@ -419,21 +434,18 @@ def build(options: Options, tmp_path: Path) -> None:  # noqa: ARG001
                 check=True,
                 stdout=subprocess.DEVNULL,
             )
-        except subprocess.CalledProcessError:
-            print(
-                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.
-                    """
-                ),
-                file=sys.stderr,
+        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.
+                """
             )
-            sys.exit(2)
+            raise errors.ConfigurationError(msg) from error
 
         try:
             ids_to_build = [x.identifier for x in build_step.platform_configs]
@@ -456,11 +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:
@@ -479,7 +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:

cibuildwheel/logger.py

@@ -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

cibuildwheel/macos.py

@@ -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:
@@ -166,23 +201,41 @@ 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(
-        python_configuration.version, base_python, venv_path, dependency_constraint_flags
+        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()
@@ -199,43 +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")
@@ -243,8 +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:
@@ -303,10 +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:
@@ -335,6 +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
@@ -352,13 +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:
@@ -384,15 +476,14 @@ def build(options: Options, tmp_path: Path) -> None:
                 extra_flags += build_frontend.args
 
                 build_env = env.copy()
-                build_env["VIRTUALENV_PIP"] = get_pip_version(env)
+                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
                     )
-                    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
+                    combine_constraints(
+                        build_env, constraint_path, identifier_tmp_dir if use_uv else None
                     )
 
                 if build_frontend.name == "pip":
@@ -410,10 +501,12 @@ def build(options: Options, tmp_path: Path) -> None:
                         *extra_flags,
                         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)
+                    if use_uv:
+                        extra_flags.append("--installer=uv")
                     call(
                         "python",
                         "-m",
@@ -543,15 +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)
@@ -560,25 +656,31 @@ 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)
 
-                    # TODO remove me once virtualenv provides pip>=24.1b1
-                    if config.version == "3.13":
-                        call("python", "-m", "pip", "install", "pip>=24.1b1", env=virtualenv_env)
-
                     if build_options.before_test:
                         before_test_prepared = prepare_command(
                             build_options.before_test,
@@ -605,18 +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,
                         )
@@ -639,18 +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

cibuildwheel/options.py

@@ -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,
         )
 
 
@@ -597,18 +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":
@@ -680,9 +677,8 @@ class Options:
             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)
+                msg = f"Failed to parse container config. {e}"
+                raise errors.ConfigurationError(msg) from e
 
             return BuildOptions(
                 globals=self.globals,
@@ -862,6 +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)

cibuildwheel/pyodide.py

@@ -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

cibuildwheel/resources/build-platforms.toml

@@ -120,12 +120,15 @@ python_configurations = [
   { 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/3.12.3/python-3.12.3-macos11.pkg" },
-  { identifier = "cp312-macosx_arm64", version = "3.12", url = "https://www.python.org/ftp/python/3.12.3/python-3.12.3-macos11.pkg" },
-  { identifier = "cp312-macosx_universal2", version = "3.12", url = "https://www.python.org/ftp/python/3.12.3/python-3.12.3-macos11.pkg" },
-  { identifier = "cp313-macosx_x86_64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b1-macos11.pkg" },
-  { identifier = "cp313-macosx_arm64", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b1-macos11.pkg" },
-  { identifier = "cp313-macosx_universal2", version = "3.13", url = "https://www.python.org/ftp/python/3.13.0/python-3.13.0b1-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" },
@@ -149,20 +152,25 @@ python_configurations = [
   { identifier = "cp310-win_amd64", version = "3.10.11", 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 = "3.12.3", arch = "32" },
-  { identifier = "cp312-win_amd64", version = "3.12.3", arch = "64" },
-  { identifier = "cp313-win32", version = "3.13.0-b1", arch = "32" },
-  { identifier = "cp313t-win32", version = "3.13.0-b1", arch = "32" },
-  { identifier = "cp313-win_amd64", version = "3.13.0-b1", arch = "64" },
-  { identifier = "cp313t-win_amd64", version = "3.13.0-b1", 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 = "3.11.9", arch = "ARM64" },
-  { identifier = "cp312-win_arm64", version = "3.12.3", arch = "ARM64" },
-  { identifier = "cp313-win_arm64", version = "3.13.0-b1", arch = "ARM64" },
-  { identifier = "cp313t-win_arm64", version = "3.13.0-b1", 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-v7.3.16-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" },
+]

cibuildwheel/resources/cibuildwheel.schema.json

@@ -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": {
@@ -765,6 +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"
+        }
+      }
     }
   }
 }

cibuildwheel/resources/constraints-pyodide312.txt

@@ -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

cibuildwheel/resources/constraints-python310.txt

@@ -14,7 +14,7 @@ importlib-metadata==7.1.0
     # via build
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -26,9 +26,9 @@ pyproject-hooks==1.1.0
     # via build
 tomli==2.0.1
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in
-zipp==3.18.2
+zipp==3.19.2
     # via importlib-metadata

cibuildwheel/resources/constraints-python311.txt

@@ -12,7 +12,7 @@ filelock==3.14.0
     # via virtualenv
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -22,7 +22,7 @@ platformdirs==4.2.2
     # via virtualenv
 pyproject-hooks==1.1.0
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in

cibuildwheel/resources/constraints-python312.txt

@@ -12,7 +12,7 @@ filelock==3.14.0
     # via virtualenv
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -22,7 +22,7 @@ platformdirs==4.2.2
     # via virtualenv
 pyproject-hooks==1.1.0
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in

cibuildwheel/resources/constraints-python313.txt

@@ -12,17 +12,17 @@ filelock==3.14.0
     # via virtualenv
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
-pip==24.1b1
+pip==24.1b2
     # via -r cibuildwheel/resources/constraints.in
 platformdirs==4.2.2
     # via virtualenv
 pyproject-hooks==1.1.0
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in

cibuildwheel/resources/constraints-python38.txt

@@ -14,7 +14,7 @@ importlib-metadata==7.1.0
     # via build
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -26,9 +26,9 @@ pyproject-hooks==1.1.0
     # via build
 tomli==2.0.1
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in
-zipp==3.18.2
+zipp==3.19.2
     # via importlib-metadata

cibuildwheel/resources/constraints-python39.txt

@@ -14,7 +14,7 @@ importlib-metadata==7.1.0
     # via build
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -26,9 +26,9 @@ pyproject-hooks==1.1.0
     # via build
 tomli==2.0.1
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in
-zipp==3.18.2
+zipp==3.19.2
     # via importlib-metadata

cibuildwheel/resources/constraints.txt

@@ -12,7 +12,7 @@ filelock==3.14.0
     # via virtualenv
 macholib==1.16.3
     # via delocate
-packaging==24.0
+packaging==24.1
     # via
     #   build
     #   delocate
@@ -22,7 +22,7 @@ platformdirs==4.2.2
     # via virtualenv
 pyproject-hooks==1.1.0
     # via build
-typing-extensions==4.11.0
+typing-extensions==4.12.2
     # via delocate
 virtualenv==20.26.2
     # via -r cibuildwheel/resources/constraints.in

cibuildwheel/resources/defaults.toml

@@ -46,3 +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]

cibuildwheel/resources/free-threaded-enable-313.xml

@@ -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>

cibuildwheel/resources/nodejs.toml

@@ -0,0 +1,2 @@
+url = "https://nodejs.org/dist/"
+v20 = "v20.14.0"

cibuildwheel/resources/pinned_docker_images.cfg

@@ -1,54 +1,54 @@
 [x86_64]
 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_64:2024-05-13-0983f6f
+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_64:2024-05-13-0983f6f
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_x86_64:2024-05-13-0983f6f
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_x86_64:2024-05-13-0983f6f
+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_i686:2024-04-29-76807b8
 manylinux2010 = quay.io/pypa/manylinux2010_i686:2022-08-05-4535177
-manylinux2014 = quay.io/pypa/manylinux2014_i686:2024-05-13-0983f6f
+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_i686:2024-05-13-0983f6f
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_i686:2024-05-13-0983f6f
+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_64:2024-05-13-0983f6f
+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_64:2024-05-13-0983f6f
+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_i686:2024-05-13-0983f6f
+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_aarch64:2024-05-13-0983f6f
+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_aarch64:2024-05-13-0983f6f
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_aarch64:2024-05-13-0983f6f
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_aarch64:2024-05-13-0983f6f
+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:2024-05-13-0983f6f
+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:2024-05-13-0983f6f
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_ppc64le:2024-05-13-0983f6f
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_ppc64le:2024-05-13-0983f6f
+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:2024-05-13-0983f6f
+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:2024-05-13-0983f6f
-musllinux_1_1 = quay.io/pypa/musllinux_1_1_s390x:2024-05-13-0983f6f
-musllinux_1_2 = quay.io/pypa/musllinux_1_2_s390x:2024-05-13-0983f6f
+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_aarch64:2024-05-13-0983f6f
+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_aarch64:2024-05-13-0983f6f
+manylinux_2_28 = quay.io/pypa/manylinux_2_28_aarch64:2024.06.12-1
 

cibuildwheel/typing.py

@@ -22,8 +22,8 @@ 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):

cibuildwheel/util.py

@@ -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"
 
 
@@ -195,7 +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]
@@ -334,6 +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()
@@ -343,12 +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)
 
@@ -373,7 +435,7 @@ class DependencyConstraints:
             return self.base_file_path.name
 
 
-BuildFrontendName = Literal["pip", "build"]
+BuildFrontendName = Literal["pip", "build", "build[uv]"]
 
 
 @dataclass(frozen=True)
@@ -385,8 +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)
@@ -534,6 +596,38 @@ def get_pip_version(env: Mapping[str, str]) -> str:
     return pip_version
 
 
+@lru_cache(maxsize=None)
+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(".")
@@ -599,48 +693,64 @@ def _parse_constraints_for_virtualenv(
 
 
 def virtualenv(
-    version: str, 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(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")
+    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
 
 
@@ -782,3 +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
+    )

cibuildwheel/windows.py

@@ -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,
@@ -96,11 +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"
@@ -226,7 +223,7 @@ 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
@@ -249,10 +246,19 @@ 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(
-        python_configuration.version, base_python, venv_path, dependency_constraint_flags
+        python_configuration.version,
+        base_python,
+        venv_path,
+        dependency_constraint_flags,
+        use_uv=use_uv,
     )
 
     # set up environment variables for run_with_env
@@ -260,19 +266,14 @@ def setup_python(
     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,
@@ -280,20 +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)
 
@@ -303,23 +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":
@@ -331,13 +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:
@@ -365,6 +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
@@ -380,13 +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:
@@ -415,26 +413,14 @@ def build(options: Options, tmp_path: Path) -> None:
                 extra_flags += build_frontend.args
 
                 build_env = env.copy()
-                build_env["VIRTUALENV_PIP"] = get_pip_version(env)
+                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
                     )
-                    # 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
-                    )
+                    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)
@@ -451,10 +437,12 @@ def build(options: Options, tmp_path: Path) -> None:
                         *extra_flags,
                         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)
+                    if use_uv:
+                        extra_flags.append("--installer=uv")
                     call(
                         "python",
                         "-m",
@@ -508,12 +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(
@@ -522,14 +518,11 @@ 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)
 
-                # TODO remove me once virtualenv provides pip>=24.1b1
-                if config.version.startswith("3.13."):
-                    call("python", "-m", "pip", "install", "--pre", "-U", "pip", env=virtualenv_env)
-
                 if build_options.before_test:
                     before_test_prepared = prepare_command(
                         build_options.before_test,
@@ -538,9 +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,
@@ -548,7 +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
@@ -567,11 +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
@@ -580,7 +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

docs/changelog.md

@@ -4,6 +4,33 @@ 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)

docs/contributing.md

@@ -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.

docs/faq.md

@@ -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@v2.18.1
+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==2.18.1
+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:
@@ -328,7 +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==2.18.1 --output-dir wheelhouse
+pipx run cibuildwheel==2.19.1 --output-dir wheelhouse
 pipx run twine upload wheelhouse/*.whl
 ```
 

docs/options.md

@@ -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.
 
@@ -309,6 +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
@@ -474,6 +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
@@ -619,7 +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:
 
@@ -631,17 +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
 
@@ -656,6 +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"
@@ -670,6 +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}
@@ -684,7 +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
@@ -715,7 +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
 
@@ -788,7 +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.
@@ -847,7 +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
 
@@ -912,7 +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
 
@@ -993,6 +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.
@@ -1006,7 +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.
@@ -1017,6 +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"
@@ -1281,7 +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
@@ -1339,7 +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
 
@@ -1402,7 +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
 
@@ -1462,7 +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
 
@@ -1502,7 +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
 
@@ -1575,13 +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
 
@@ -1601,12 +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.

docs/setup.md

@@ -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==2.18.1
+            run: pipx run cibuildwheel==2.19.1
 
           - uses: actions/upload-artifact@v4
             with:
@@ -191,7 +198,7 @@ To build Linux, Mac, and Windows wheels using GitHub Actions, create a `.github/
           - uses: actions/setup-python@v5
 
           - name: Install cibuildwheel
-            run: python -m pip install cibuildwheel==2.18.1
+            run: python -m pip install cibuildwheel==2.19.1
 
           - name: Build wheels
             run: python -m cibuildwheel --output-dir wheelhouse

docs/working-examples.md

@@ -14,9 +14,9 @@ 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. |
-| [duckdb][]                        | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | DuckDB is an in-process SQL OLAP Database Management System |
 | [Kivy][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Open source UI framework written in Python, running on Windows, Linux, macOS, Android and iOS |
 | [MemRay][]                        | ![github icon][] | ![linux icon][] | Memray is a memory profiler for Python |
 | [Triton][]                        | ![github icon][] | ![linux icon][] | Self hosted runners |
@@ -108,8 +108,8 @@ title: Working examples
 | [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. |
+| [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. |
@@ -123,9 +123,9 @@ title: Working examples
 [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
-[duckdb]: https://github.com/duckdb/duckdb
 [Kivy]: https://github.com/kivy/kivy
 [MemRay]: https://github.com/bloomberg/memray
 [Triton]: https://github.com/openai/triton
@@ -217,8 +217,8 @@ title: Working examples
 [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
+[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

examples/appveyor-minimal.yml

@@ -12,7 +12,7 @@ stack: python 3.7
 init:
 - cmd: set PATH=C:\Python37;C:\Python37\Scripts;%PATH%
 
-install: python -m pip install cibuildwheel==2.18.1
+install: python -m pip install cibuildwheel==2.19.1
 
 build_script: python -m cibuildwheel --output-dir wheelhouse
 

examples/azure-pipelines-minimal.yml

@@ -6,7 +6,7 @@ jobs:
     - bash: |
         set -o errexit
         python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==2.18.1
+        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==2.18.1
+        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==2.18.1
+        pip install cibuildwheel==2.19.1
       displayName: Install dependencies
     - bash: cibuildwheel --output-dir wheelhouse .
       displayName: Build wheels

examples/circleci-minimal.yml

@@ -11,7 +11,7 @@ jobs:
       - run:
           name: Build the Linux wheels.
           command: |
-            pip3 install --user cibuildwheel==2.18.1
+            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==2.18.1
+            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==2.18.1
+            pip3 install cibuildwheel==2.19.1
             cibuildwheel --output-dir wheelhouse
       - store_artifacts:
           path: wheelhouse/

examples/cirrus-ci-intel-mac.yml

@@ -1,6 +1,6 @@
 build_and_store_wheels: &BUILD_AND_STORE_WHEELS
   install_cibuildwheel_script:
-    - python -m pip install cibuildwheel==2.18.1
+    - python -m pip install cibuildwheel==2.19.1
   run_cibuildwheel_script:
     - cibuildwheel
   wheels_artifacts:

examples/cirrus-ci-minimal.yml

@@ -1,6 +1,6 @@
 build_and_store_wheels: &BUILD_AND_STORE_WHEELS
   install_cibuildwheel_script:
-    - python -m pip install cibuildwheel==2.18.1
+    - python -m pip install cibuildwheel==2.19.1
   run_cibuildwheel_script:
     - cibuildwheel
   wheels_artifacts:

examples/github-deploy.yml

@@ -23,7 +23,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.18.1
+        uses: pypa/cibuildwheel@v2.19.1
 
       - uses: actions/upload-artifact@v4
         with:

examples/github-minimal.yml

@@ -15,7 +15,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.18.1
+        uses: pypa/cibuildwheel@v2.19.1
         # env:
         #   CIBW_SOME_OPTION: value
         #    ...

examples/github-with-qemu.yml

@@ -21,7 +21,7 @@ jobs:
           platforms: all
 
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.18.1
+        uses: pypa/cibuildwheel@v2.19.1
         env:
           # configure cibuildwheel to build native archs ('auto'), and some
           # emulated ones

examples/gitlab-minimal.yml

@@ -12,7 +12,7 @@ linux:
     DOCKER_TLS_CERTDIR: ""
   script:
     - curl -sSL https://get.docker.com/ | sh
-    - python -m pip install cibuildwheel==2.18.1
+    - 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==2.18.1
+    - py -m pip install cibuildwheel==2.19.1
   script:
     - py -m cibuildwheel --output-dir wheelhouse --platform windows
   artifacts:

examples/gitlab-with-qemu.yml

@@ -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==2.18.1
+    - 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:

examples/travis-ci-deploy.yml

@@ -20,7 +20,7 @@ jobs:
         - ln -s /c/Python38/python.exe /c/Python38/python3.exe
 
 install:
-  - python3 -m pip install cibuildwheel==2.18.1
+  - python3 -m pip install cibuildwheel==2.19.1
 
 script:
   # build the wheels, put them into './dist'

examples/travis-ci-minimal.yml

@@ -26,7 +26,7 @@ jobs:
         - ln -s /c/Python38/python.exe /c/Python38/python3.exe
 
 install:
-  - python3 -m pip install cibuildwheel==2.18.1
+  - python3 -m pip install cibuildwheel==2.19.1
 
 script:
   # build the wheels, put them into './wheelhouse'

examples/travis-ci-test-and-deploy.yml

@@ -54,7 +54,7 @@ jobs:
     - stage: deploy
       name: Build and deploy Linux wheels
       services: docker
-      install: python3 -m pip install cibuildwheel==2.18.1 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==2.18.1 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
 

noxfile.py

@@ -70,6 +70,8 @@ def update_constraints(session: nox.Session) -> None:
     Update the dependencies inplace.
     """
 
+    resources = Path("cibuildwheel/resources")
+
     if session.venv_backend != "uv":
         session.install("uv>=0.1.23")
 
@@ -79,22 +81,42 @@ def update_constraints(session: nox.Session) -> None:
         # 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",
-            "cibuildwheel/resources/constraints.in",
-            f"--output-file=cibuildwheel/resources/constraints-python{python_version.replace('.', '')}.txt",
+            resources / "constraints.in",
+            f"--output-file={output_file}",
             env=env,
         )
-    RESOURCES = DIR / "cibuildwheel" / "resources"
+
     shutil.copyfile(
-        RESOURCES / "constraints-python312.txt",
-        RESOURCES / "constraints.txt",
+        resources / "constraints-python312.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,
+        )
+
 
 @nox.session
 def update_pins(session: nox.Session) -> None:
@@ -105,6 +127,7 @@ def update_pins(session: nox.Session) -> None:
     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(reuse_venv=True)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "cibuildwheel"
-version = "2.18.1"
+version = "2.19.1"
 description = "Build Python wheels on CI with minimal configuration."
 readme = "README.md"
 license = "BSD-2-Clause"
@@ -78,6 +78,7 @@ test = [
     "tomli_w",
     "validate-pyproject",
 ]
+uv = ["uv"]
 
 [project.scripts]
 cibuildwheel = "cibuildwheel.__main__:main"
@@ -92,7 +93,12 @@ 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"]
@@ -176,6 +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]

test/conftest.py

@@ -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]:

test/test_abi_variants.py

@@ -20,7 +20,7 @@ limited_api_project = test_projects.new_c_project(
         CAN_USE_ABI3 = IS_CPYTHON and not Py_GIL_DISABLED
         cmdclass = {}
         extension_kwargs = {}
-        if CAN_USE_ABI3 and 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):
@@ -33,7 +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
     """
     ),
@@ -48,23 +48,32 @@ 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={
             # free_threaded and PyPy do not have a Py_LIMITED_API equivalent, just build one of those
-            "CIBW_BUILD": "cp3?-* cp31?-* cp313t-* pp310-*"
+            # 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 ("-pp310" in w or "-pp" not in w)
-        and "-cp39" not in w
-        and ("-cp313t" in w or "-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)
 
 
@@ -183,9 +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-* cp313t-* pp310-*",
+            "CIBW_BUILD": "cp38-* cp{}{}-* cp313t-* pp310-*".format(*utils.SINGLE_PYTHON_VERSION),
         },
     )
 
@@ -196,4 +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

test/test_before_all.py

@@ -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)

test/test_before_build.py

@@ -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)

test/test_before_test.py

@@ -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",
         },
     )

test/test_build_frontend_args.py

@@ -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

test/test_build_skip.py

@@ -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)

test/test_container_engine.py

@@ -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()

test/test_cpp_standards.py

@@ -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)

test/test_custom_repair_wheel.py

@@ -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-")

test/test_dependency_versions.py

@@ -53,7 +53,7 @@ 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":
@@ -79,7 +79,7 @@ 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,
         },
     )
 
@@ -93,7 +93,7 @@ def test_pinned_versions(tmp_path, python_version, build_frontend_env):
     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")
 
@@ -130,7 +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,
         },
     )
 

test/test_emscripten.py

@@ -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)

test/test_emulation.py

@@ -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)
 

test/test_environment.py

@@ -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)

test/test_from_sdist.py

@@ -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

test/test_macos_archs.py

@@ -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")
@@ -186,19 +185,21 @@ 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)
 
 

test/test_musllinux_X_Y_only.py

@@ -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)

test/test_projects/c.py

@@ -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',

test/test_pure_wheel.py

@@ -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()

test/test_subdir_package.py

@@ -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()

test/test_testing.py

@@ -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)
 
 

test/test_wheel_tag.py

@@ -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)

test/test_windows.py

@@ -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)

test/utils.py

@@ -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:
@@ -67,7 +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.
@@ -99,6 +114,9 @@ def cibuildwheel_run(
 
     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(
             [
@@ -119,17 +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(
@@ -141,6 +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.
@@ -170,6 +184,8 @@ def expected_wheels(
     if musllinux_versions is None:
         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",
@@ -180,9 +196,8 @@ def expected_wheels(
             "cp311-cp311",
             "cp312-cp312",
             "cp313-cp313",
+            "cp313-cp313t",
         ]
-        if platform != "macos":
-            python_abi_tags.append("cp313-cp313t")
 
         if machine_arch in ["x86_64", "AMD64", "x86", "aarch64"]:
             python_abi_tags += [
@@ -201,20 +216,37 @@ def expected_wheels(
                 "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:
@@ -244,18 +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)
@@ -278,6 +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

unit_test/main_tests/main_options_test.py

@@ -344,6 +344,28 @@ def test_before_all(before_all, platform_specific, platform, intercepted_build_a
     assert build_options.before_all == (before_all or "")
 
 
+@pytest.mark.parametrize("method", ["unset", "command_line", "env_var"])
+def test_debug_traceback(monkeypatch, method, capfd):
+    if method == "command_line":
+        monkeypatch.setattr(sys, "argv", [*sys.argv, "--debug-traceback"])
+    elif method == "env_var":
+        monkeypatch.setenv("CIBW_DEBUG_TRACEBACK", "TRUE")
+
+    # set an option that produces a configuration error
+    monkeypatch.setenv("CIBW_BUILD_FRONTEND", "invalid_value")
+
+    with pytest.raises(SystemExit) as exit:
+        main()
+    assert exit.value.code == 2
+
+    _, err = capfd.readouterr()
+
+    if method == "unset":
+        assert "Traceback (most recent call last)" not in err
+    else:
+        assert "Traceback (most recent call last)" in err
+
+
 def test_defaults(platform, intercepted_build_args):
     main()
 

unit_test/main_tests/main_platform_test.py

@@ -264,3 +264,16 @@ def test_only_overrides_env_vars(monkeypatch, intercepted_build_args, envvar_nam
     assert options.globals.build_selector.skip_config == ""
     assert options.platform == "linux"
     assert options.globals.architectures == Architecture.all_archs("linux")
+
+
+def test_pyodide_on_windows(monkeypatch, capsys):
+    monkeypatch.setattr(sys, "platform", "win32")
+    monkeypatch.setattr(sys, "argv", [*sys.argv, "--only", "cp312-pyodide_wasm32"])
+
+    with pytest.raises(SystemExit) as exit:
+        main()
+
+    _, err = capsys.readouterr()
+
+    assert exit.value.code == 2
+    assert "cibuildwheel: Building for pyodide is not supported on Windows" in err

unit_test/options_test.py

@@ -7,6 +7,7 @@ from pathlib import Path
 
 import pytest
 
+from cibuildwheel import errors
 from cibuildwheel.__main__ import get_build_identifiers, get_platform_module
 from cibuildwheel.bashlex_eval import local_environment_executor
 from cibuildwheel.environment import parse_environment
@@ -127,7 +128,8 @@ def test_passthrough_evil(tmp_path, monkeypatch, env_var_value):
 
 
 xfail_env_parse = pytest.mark.xfail(
-    raises=SystemExit, reason="until we can figure out the right way to quote these values"
+    raises=errors.ConfigurationError,
+    reason="until we can figure out the right way to quote these values",
 )