'Bump version: v1.11.0'

'Bump version: v1.10.1'
fix: occasional nuget error (#653 )
2021-05-01 18:24:56 +01:00 · 2021-05-01 18:23:18 +01:00 · 2021-04-30 17:41:19 -04:00 · 2021-04-30 12:20:11 +01:00 · 2021-04-30 11:14:13 +01:00 · 2021-04-30 11:10:54 +01:00
84 changed files with 2447 additions and 734 deletions
@@ -21,6 +21,7 @@ jobs:

  test:
    name: Test cibuildwheel on ${{ matrix.os }}
+    needs: pre-commit
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
@@ -38,11 +39,6 @@ jobs:
      run: |
        python -m pip install -e ".[dev]"

-    - name: Install Visual C++ for Python 2.7
-      if: runner.os == 'Windows'
-      run: |
-        choco install vcpython27 -f -y
-
    - name: Get PR labels
      id: pr-labels
      uses: joerick/pr-labels-action@v1.0.6
@@ -52,12 +48,25 @@ jobs:
      run: |
        python bin/sample_build.py

+    - name: Get some sample wheels
+      run: |
+        python -m test.test_projects test.test_0_basic.basic_project sample_proj
+        cibuildwheel --output-dir wheelhouse sample_proj
+      env:
+        CIBW_ARCHS_MACOS: x86_64 universal2 arm64
+
+    - uses: actions/upload-artifact@v2
+      with:
+        name: sample_wheels
+        path: wheelhouse
+
    - name: Test cibuildwheel
      run: |
        python ./bin/run_tests.py

  test-emulated:
    name: Test emulated cibuildwheel using qemu
+    needs: pre-commit
    runs-on: ubuntu-latest
    timeout-minutes: 180
    steps:
@@ -23,7 +23,7 @@ jobs:
    - name: "Run update: python configs"
      run: python ./bin/update_pythons.py --force
    - name: Create Pull Request
-      if: github.ref == 'refs/heads/master'
+      if: github.ref == 'refs/heads/master' && github.repository == 'joerick/cibuildwheel'
      uses: peter-evans/create-pull-request@v3
      with:
        commit-message: Update dependencies
@@ -105,3 +105,12 @@ env3?/

 # MyPy cache
 .mypy_cache/
+
+# Output cache for setup.py checker
+all_known_setup.yaml
+
+# mkdocs
+site/
+
+# Virtual environments
+venv*
@@ -6,40 +6,67 @@ repos:
  - id: check-case-conflict
  - id: check-merge-conflict
  - id: check-yaml
+  - id: check-toml
+  - id: debug-statements
  - id: end-of-file-fixer
    exclude: (cibuildwheel/resources/pinned_docker_images.cfg)|(.svg$)
  - id: mixed-line-ending
  - id: trailing-whitespace

 - repo: https://github.com/PyCQA/isort
-  rev: 5.7.0
+  rev: 5.8.0
  hooks:
  - id: isort

 - repo: https://github.com/psf/black
-  rev: 20.8b1
+  rev: 21.4b1
  hooks:
  - id: black
-    files: ^bin/update_pythons.py$
-    args: ["--line-length=120"]
+    files: ^bin/update_pythons.py|setup.py$
+
+- repo: https://github.com/asottile/setup-cfg-fmt
+  rev: v1.17.0
+  hooks:
+  - id: setup-cfg-fmt
+    stages: [manual]

 - repo: https://github.com/pre-commit/mirrors-mypy
-  rev: v0.790
+  rev: v0.812
  hooks:
  - id: mypy
-    files: ^(cibuildwheel/|test/|bin/projects.py|bin/update_pythons.py|unit_test/)
-    pass_filenames: false
-    additional_dependencies: [packaging, click]
+    exclude: ^(bin/|cibuildwheel/resources/).*py$
+    additional_dependencies: [packaging]
+    args: ["--python-version=3.6", "--ignore-missing-imports", "--scripts-are-modules"]
+  - id: mypy
+    name: mypy 3.7+ on bin/
+    files: ^bin/.*py$
+    additional_dependencies: [packaging]
+    args: ["--python-version=3.7", "--ignore-missing-imports", "--scripts-are-modules"]

 - repo: https://github.com/asottile/pyupgrade
-  rev: v2.7.4
+  rev: v2.13.0
  hooks:
  - id: pyupgrade
+    name: PyUpgrade 3.6+
    args: ["--py36-plus"]
+    exclude: ^bin/
+  - id: pyupgrade
+    name: PyUpgrade 3.7+ on bin
+    exclude: ^(cibuildwheel|unit_test|test)/
+    args: ["--py37-plus"]

- repo: https://gitlab.com/pycqa/flake8
-  rev: 3.8.4
+- repo: https://github.com/PyCQA/flake8
+  rev: 3.9.1
  hooks:
  - id: flake8
    exclude: cibuildwheel/resources/
    additional_dependencies: [flake8-bugbear]
+
+- repo: local
+  hooks:
+  - id: disallow-caps
+    name: Disallow improper capitalization
+    language: pygrep
+    entry: PyBind|Numpy|Cmake|Github
+    types:
+    - markdown
@@ -6,9 +6,9 @@ mkdocs:
  configuration: mkdocs.yml

 python:
-  version: 3.7
+  version: 3.8
  install:
    - method: pip
      path: .
      extra_requirements:
-        - dev
+        - docs
@@ -36,9 +36,9 @@ jobs:
      os: windows
      language: shell
      before_install:
-       - choco install python3 --version 3.6.8 --no-progress -y
-       # Update root certificates to fix SSL error; see http://www.chawn.com/RootCerts.htm
-       - powershell "md C:\temp\certs; CertUtil -generateSSTFromWU C:\temp\certs\RootStore.sst; Get-ChildItem -Path C:\\temp\certs\Rootstore.sst | Import-Certificate -CertStoreLocation Cert:\\LocalMachine\\Root\\ | out-null"
+        - choco upgrade python3 -y --version 3.6.8 --limit-output
+        # Update root certificates to fix SSL error; see http://www.chawn.com/RootCerts.htm
+        - powershell "md C:\temp\certs; CertUtil -generateSSTFromWU C:\temp\certs\RootStore.sst; Get-ChildItem -Path C:\\temp\certs\Rootstore.sst | Import-Certificate -CertStoreLocation Cert:\\LocalMachine\\Root\\ | out-null"
      env:
        - PYTHON=C:\\Python36\\python

@@ -1,7 +1,14 @@
 cibuildwheel
 ============

-[![PyPI](https://img.shields.io/pypi/v/cibuildwheel.svg)](https://pypi.python.org/pypi/cibuildwheel) [![Documentation Status](https://readthedocs.org/projects/cibuildwheel/badge/?version=stable)](https://cibuildwheel.readthedocs.io/en/stable/?badge=stable) [![Build Status](https://travis-ci.org/joerick/cibuildwheel.svg?branch=master)](https://travis-ci.org/joerick/cibuildwheel) [![Build status](https://ci.appveyor.com/api/projects/status/wbsgxshp05tt1tif/branch/master?svg=true)](https://ci.appveyor.com/project/joerick/cibuildwheel/branch/master) [![CircleCI](https://circleci.com/gh/joerick/cibuildwheel.svg?style=svg)](https://circleci.com/gh/joerick/cibuildwheel) [![Build Status](https://dev.azure.com/joerick0429/cibuildwheel/_apis/build/status/joerick.cibuildwheel?branchName=master)](https://dev.azure.com/joerick0429/cibuildwheel/_build/latest?definitionId=2&branchName=master)
+[![PyPI](https://img.shields.io/pypi/v/cibuildwheel.svg)](https://pypi.python.org/pypi/cibuildwheel)
+[![Documentation Status](https://readthedocs.org/projects/cibuildwheel/badge/?version=stable)](https://cibuildwheel.readthedocs.io/en/stable/?badge=stable)
+[![Actions Status](https://github.com/joerick/cibuildwheel/workflows/Test/badge.svg)](https://github.com/joerick/cibuildwheel/actions)
+[![Travis Status](https://img.shields.io/travis/joerick/cibuildwheel/master?logo=travis)](https://travis-ci.org/joerick/cibuildwheel)
+[![AppVeyor status](https://ci.appveyor.com/api/projects/status/wbsgxshp05tt1tif/branch/master?svg=true)](https://ci.appveyor.com/project/joerick/cibuildwheel/branch/master)
+[![CircleCI Status](https://img.shields.io/circleci/build/gh/joerick/cibuildwheel/master?logo=circleci)](https://circleci.com/gh/joerick/cibuildwheel)
+[![Azure Status](https://dev.azure.com/joerick0429/cibuildwheel/_apis/build/status/joerick.cibuildwheel?branchName=master)](https://dev.azure.com/joerick0429/cibuildwheel/_build/latest?definitionId=2&branchName=master)
+

 [Documentation](https://cibuildwheel.readthedocs.org)

@@ -15,26 +22,24 @@ Python wheels are great. Building them across **Mac, Linux, Windows**, on **mult
 What does it do?
 ----------------

-|   | macOS x86_64 | Windows 64bit | Windows 32bit | manylinux x86_64 | manylinux i686 | manylinux aarch64 | manylinux ppc64le | manylinux s390x |
-|---|---|---|---|---|---|---|---|---|
-| CPython 2.7     | ✅ | ✅¹ | ✅¹ | ✅ | ✅ |    |    |    |
-| CPython 3.5     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅² | ✅² | ✅³ |
-| CPython 3.6     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅² | ✅² | ✅³ |
-| CPython 3.7     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅² | ✅² | ✅³ |
-| CPython 3.8     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅² | ✅² | ✅³ |
-| CPython 3.9     | ✅ | ✅  | ✅  | ✅ | ✅ | ✅² | ✅² | ✅³ |
-| PyPy 2.7 v7.3.3 | ✅ |    | ✅  | ✅ |    |    |    |    |
-| PyPy 3.6 v7.3.3 | ✅ |    | ✅  | ✅ |    |    |    |    |
-| PyPy 3.7 (beta) v7.3.3 | ✅ |    | ✅  | ✅ |    |    |    |    |
+|   | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | manylinux x86_64 | manylinux i686 | manylinux aarch64 | manylinux ppc64le | manylinux s390x |
+|---|---|---|---|---|---|---|---|---|---|
+| CPython 2.7     | ✅ |   | ✅¹ | ✅¹ | ✅ | ✅ |    |    |   |
+| CPython 3.5     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| CPython 3.6     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| CPython 3.7     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| CPython 3.8     | ✅ |   | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| CPython 3.9     | ✅ | ✅ | ✅  | ✅  | ✅ | ✅ | ✅ | ✅ | ✅ |
+| PyPy 2.7 v7.3.3 | ✅ |    |    | ✅  | ✅ |    |    |    |   |
+| PyPy 3.6 v7.3.3 | ✅ |    |    | ✅  | ✅ |    |    |    |   |
+| PyPy 3.7 (beta) v7.3.3 | ✅ | |  | ✅  | ✅ |    |    |   |    |

-<sup>¹ Not supported on Travis</sup><br>
-<sup>² Only supported on Travis</sup><br>
-<sup>³ Beta support until Travis CI fixes <a href="https://travis-ci.community/t/no-space-left-on-device-for-system-z/5954/11">a bug</a></sup><br>
+<sup>¹ Only using a workaround with a newer compiler; Microsoft removed the 2008 compiler for Python 2.7 in April 2021.</sup><br>

- Builds manylinux, macOS, and Windows wheels for CPython and PyPy
+- Builds manylinux, macOS 10.9+, and Windows wheels for CPython and PyPy
 - Works on GitHub Actions, Azure Pipelines, Travis CI, AppVeyor, CircleCI, and GitLab CI
 - Bundles shared library dependencies on Linux and macOS through [auditwheel](https://github.com/pypa/auditwheel) and [delocate](https://github.com/matthew-brett/delocate)
- Runs the library test suite against the wheel-installed version of your library
+- Runs your library's tests against the wheel-installed version of your library

 Usage
 -----
@@ -43,23 +48,23 @@ Usage

 |                 | Linux | macOS | Windows | Linux ARM |
 |-----------------|-------|-------|---------|--------------|
-| GitHub Actions  | ✅    | ✅    | ✅      | ✴️¹           |
-| Azure Pipelines | ✅    | ✅    | ✅      | ✴️¹           |
+| GitHub Actions  | ✅    | ✅    | ✅      | ✅¹           |
+| Azure Pipelines | ✅    | ✅    | ✅      |              |
 | Travis CI       | ✅    | ✅    | ✅      | ✅           |
 | AppVeyor        | ✅    | ✅    | ✅      |              |
 | CircleCI        | ✅    | ✅    |         |              |
 | Gitlab CI       | ✅    |       |         |              |

-<sup>¹ Requires a "third-party build host"; expected to work with cibuildwheel but not directly tested by our CI.</sup><br>
+<sup>¹ [Requires emulation](https://cibuildwheel.readthedocs.io/en/stable/faq/#emulation), distributed separately. Other services may also support Linux ARM through emulation or third-party build hosts, but these are not tested in our CI.</sup><br>

-`cibuildwheel` is not intended to run on your development machine. Because it uses system Python from Python.org it will try to install packages globally - not what you expect from a build tool! Instead, isolated CI services like those mentioned above are ideal.
+`cibuildwheel` is not intended to run on your development machine. Because it uses system Python from Python.org on macOS and Windows, it will try to install packages globally - not what you expect from a build tool! Instead, isolated CI services like those mentioned above are ideal. For Linux builds, it uses manylinux docker images, so those can be done locally for testing in a pinch.

 <!--intro-end-->

 Example setup
 -------------

-To build manylinux, macOS, and Windows wheels on Github Actions, you could use this `.github/workflows/wheels.yml`:
+To build manylinux, macOS, and Windows wheels on GitHub Actions, you could use this `.github/workflows/wheels.yml`:

 ```yaml
 name: Build
@@ -77,23 +82,24 @@ jobs:
    steps:
      - uses: actions/checkout@v2

+      # Used to host cibuildwheel
      - uses: actions/setup-python@v2
-        name: Install Python

      - name: Install cibuildwheel
-        run: python -m pip install cibuildwheel==1.8.0
+        run: python -m pip install cibuildwheel==1.11.0

      - name: Build wheels
        run: python -m cibuildwheel --output-dir wheelhouse
-        env:
-          CIBW_SKIP: "cp27-* pp27-*"  # skip Python 2.7 wheels
+        # to supply options, put them in 'env', like:
+        # env:
+        #   CIBW_SOME_OPTION: value

      - uses: actions/upload-artifact@v2
        with:
          path: ./wheelhouse/*.whl
 ```

-For more information, including building on Python 2, PyPI deployment, and the use of other CI services, check out the [documentation](https://cibuildwheel.readthedocs.org) and the [examples](https://github.com/joerick/cibuildwheel/tree/master/examples).
+For more information, including building on Python 2, PyPI deployment, and the use of other CI services or the dedicated GitHub Action, check out the [documentation](https://cibuildwheel.readthedocs.org) and the [examples](https://github.com/joerick/cibuildwheel/tree/master/examples).

 Options
 -------
@@ -102,7 +108,8 @@ Options
 |---|--------|-------------|
 | **Build selection** | [`CIBW_PLATFORM`](https://cibuildwheel.readthedocs.io/en/stable/options/#platform)  | Override the auto-detected target platform |
 |   | [`CIBW_BUILD`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  <br> [`CIBW_SKIP`](https://cibuildwheel.readthedocs.io/en/stable/options/#build-skip)  | Choose the Python versions to build |
-|   | [`CIBW_ARCHS_LINUX`](https://cibuildwheel.readthedocs.io/en/stable/options/#archs)  | Build non-native architectures |
+|   | [`CIBW_ARCHS`](https://cibuildwheel.readthedocs.io/en/stable/options/#archs)  | Change the architectures built on your machine by default |
+|   | [`CIBW_PROJECT_REQUIRES_PYTHON`](https://cibuildwheel.readthedocs.io/en/stable/options/#requires-python)  | Manually set the Python compatibility of your project |
 | **Build customization** | [`CIBW_ENVIRONMENT`](https://cibuildwheel.readthedocs.io/en/stable/options/#environment)  | Set environment variables needed during the build |
 |   | [`CIBW_BEFORE_ALL`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-all)  | Execute a shell command on the build system before any wheels are built. |
 |   | [`CIBW_BEFORE_BUILD`](https://cibuildwheel.readthedocs.io/en/stable/options/#before-build)  | Execute a shell command preparing each wheel's build |
@@ -140,8 +147,8 @@ Here are some repos that use cibuildwheel.
 | [pyzmq][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Python bindings for zeromq, the networking library. Uses Cython and CFFI.  |
 | [aiortc][]                        | ![github icon][] | ![apple icon][] ![linux icon][] | WebRTC and ORTC implementation for Python using asyncio. |
 | [numexpr][]                       | ![github icon][] ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Fast numerical array expression evaluator for Python, NumPy, PyTables, pandas, bcolz and more |
-| [h5py][]                          | ![azurepipelines icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | HDF5 for Python -- The h5py package is a Pythonic interface to the HDF5 binary data format. |
 | [coverage.py][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The coverage tool for Python |
+| [h5py][]                          | ![azurepipelines icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | HDF5 for Python -- The h5py package is a Pythonic interface to the HDF5 binary data format. |
 | [River][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | 🌊 Online machine learning in Python |
 | [PyAV][]                          | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Pythonic bindings for FFmpeg's libraries. |
 | [Dependency Injector][]           | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Dependency injection framework for Python, uses Windows TravisCI |
@@ -149,18 +156,22 @@ Here are some repos that use cibuildwheel.
 | [ruptures][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Extensive Cython + NumPy [pyproject.toml](https://github.com/deepcharles/ruptures/blob/master/pyproject.toml) example. |
 | [aioquic][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | QUIC and HTTP/3 implementation in Python |
 | [google neuroglancer][]           | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | WebGL-based viewer for volumetric data |
-| [AutoPy][]                        | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Includes a Windows Travis build. |
 | [pikepdf][]                       | ![azurepipelines icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python library for reading and writing PDF, powered by qpdf |
+| [AutoPy][]                        | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Includes a Windows Travis build. |
 | [Parselmouth][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python interface to the Praat software package, using pybind11, C++17 and CMake, with the core Praat static library built only once and shared between wheels. |
 | [python-rapidjson][]              | ![travisci icon][] ![gitlab icon][] ![appveyor icon][] | ![windows icon][] ![linux icon][] | Python wrapper around rapidjson |
 | [Rtree][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Rtree: spatial index for Python GIS ¶ |
+| [python-snappy][]                 | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Python bindings for the snappy google library |
+| [markupsafe][]                    | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Safely add untrusted strings to HTML/XML markup. |
 | [KDEpy][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Kernel Density Estimation in Python |
 | [cyvcf2][]                        | ![github icon][] | ![apple icon][] ![linux icon][] | cython + htslib == fast VCF and BCF processing |
 | [pybind11 cmake_example][]        | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Example pybind11 module built with a CMake-based build system |
 | [pybind11 python_example][]       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Example pybind11 module built with a Python-based build system |
+| [sourmash][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Compute and compare MinHash signatures for DNA data sets. |
 | [dd-trace-py][]                   | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Uses custom alternate arch emulation on GitHub |
 | [iminuit][]                       | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Jupyter-friendly Python interface for C++ MINUIT2 |
 | [jq.py][]                         | ![travisci icon][] | ![apple icon][] ![linux icon][] | Python bindings for jq |
+| [time-machine][]                  | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Time mocking library using only the CPython C API. |
 | [matrixprofile][]                 | ![travisci icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A Python 3 library making time series data mining tasks, utilizing matrix profile algorithms, accessible to everyone. |
 | [CTranslate2][]                   | ![github icon][] | ![apple icon][] ![linux icon][] | Includes libraries from the [Intel oneAPI toolkit](https://software.intel.com/content/www/us/en/develop/tools/oneapi/base-toolkit.html). The Linux wheels also include CUDA libraries for GPU execution. |
 | [Tokenizer][]                     | ![github icon][] ![travisci icon][] | ![apple icon][] ![linux icon][] | Fast and customizable text tokenization library with BPE and SentencePiece support |
@@ -172,8 +183,9 @@ Here are some repos that use cibuildwheel.
 | [pyjet][]                         | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | The interface between FastJet and NumPy |
 | [numpythia][]                     | ![github icon][] | ![apple icon][] ![linux icon][] | The interface between PYTHIA and NumPy |
 | [fathon][]                        | ![travisci icon][] | ![apple icon][] ![linux icon][] | python package for DFA (Detrended Fluctuation Analysis) and related algorithms |
-| [pyinstrument_cext][]             | ![travisci icon][] ![appveyor icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A simple C extension, without external dependencies |
 | [Imagecodecs (fork)][]            | ![azurepipelines icon][] | ![apple icon][] ![linux icon][] | Over 20 external dependencies in compiled libraries, custom docker image, `libomp`, `openblas` and `install_name_tool` for macOS. |
+| [pyinstrument_cext][]             | ![travisci icon][] ![appveyor icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | A simple C extension, without external dependencies |
+| [polaroid][]                      | ![github icon][] | ![apple icon][] ![linux icon][] ![windows icon][] | Full range of wheels for setuptools rust, with auto release and PyPI deploy. |
 | [xmlstarlet][]                    | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | Python 3.6+ CFFI bindings with true MSVC build. |
 | [pybind11 scikit_build_example][] | ![github icon][] | ![windows icon][] ![apple icon][] ![linux icon][] | An example combining scikit-build and pybind11 |

@@ -187,8 +199,8 @@ Here are some repos that use cibuildwheel.
 [pyzmq]: https://github.com/zeromq/pyzmq
 [aiortc]: https://github.com/aiortc/aiortc
 [numexpr]: https://github.com/pydata/numexpr
-[h5py]: https://github.com/h5py/h5py
 [coverage.py]: https://github.com/nedbat/coveragepy
+[h5py]: https://github.com/h5py/h5py
 [River]: https://github.com/online-ml/river
 [PyAV]: https://github.com/PyAV-Org/PyAV
 [Dependency Injector]: https://github.com/ets-labs/python-dependency-injector
@@ -196,18 +208,22 @@ Here are some repos that use cibuildwheel.
 [ruptures]: https://github.com/deepcharles/ruptures
 [aioquic]: https://github.com/aiortc/aioquic
 [google neuroglancer]: https://github.com/google/neuroglancer
-[AutoPy]: https://github.com/autopilot-rs/autopy
 [pikepdf]: https://github.com/pikepdf/pikepdf
+[AutoPy]: https://github.com/autopilot-rs/autopy
 [Parselmouth]: https://github.com/YannickJadoul/Parselmouth
 [python-rapidjson]: https://github.com/python-rapidjson/python-rapidjson
 [Rtree]: https://github.com/Toblerity/rtree
+[python-snappy]: https://github.com/andrix/python-snappy
+[markupsafe]: https://github.com/pallets/markupsafe
 [KDEpy]: https://github.com/tommyod/KDEpy
 [cyvcf2]: https://github.com/brentp/cyvcf2
 [pybind11 cmake_example]: https://github.com/pybind/cmake_example
 [pybind11 python_example]: https://github.com/pybind/python_example
+[sourmash]: https://github.com/dib-lab/sourmash
 [dd-trace-py]: https://github.com/DataDog/dd-trace-py
 [iminuit]: https://github.com/scikit-hep/iminuit
 [jq.py]: https://github.com/mwilliamson/jq.py
+[time-machine]: https://github.com/adamchainz/time-machine
 [matrixprofile]: https://github.com/matrix-profile-foundation/matrixprofile
 [CTranslate2]: https://github.com/OpenNMT/CTranslate2
 [Tokenizer]: https://github.com/OpenNMT/Tokenizer
@@ -219,8 +235,9 @@ Here are some repos that use cibuildwheel.
 [pyjet]: https://github.com/scikit-hep/pyjet
 [numpythia]: https://github.com/scikit-hep/numpythia
 [fathon]: https://github.com/stfbnc/fathon
-[pyinstrument_cext]: https://github.com/joerick/pyinstrument_cext
 [Imagecodecs (fork)]: https://github.com/czaki/imagecodecs_build
+[pyinstrument_cext]: https://github.com/joerick/pyinstrument_cext
+[polaroid]: https://github.com/daggy1234/polaroid
 [xmlstarlet]: https://github.com/dimitern/xmlstarlet
 [pybind11 scikit_build_example]: https://github.com/pybind/scikit_build_example

@@ -234,52 +251,57 @@ Here are some repos that use cibuildwheel.
 [apple icon]: docs/data/readme_icons/apple.svg
 [linux icon]: docs/data/readme_icons/linux.svg

-<!-- scikit-learn: 43800, last pushed 0 days ago -->
-<!-- Matplotlib: 12963, last pushed 0 days ago -->
-<!-- MyPy: 9770, last pushed 0 days ago -->
-<!-- psutil: 6990, last pushed 5 days ago -->
-<!-- scikit-image: 4143, last pushed 0 days ago -->
-<!-- twisted-iocpsupport: 4140, last pushed 7 days ago -->
-<!-- websockets: 3146, last pushed 9 days ago -->
-<!-- pyzmq: 2675, last pushed 1 days ago -->
-<!-- aiortc: 2113, last pushed 7 days ago -->
-<!-- numexpr: 1512, last pushed 16 days ago -->
-<!-- h5py: 1474, last pushed 2 days ago -->
-<!-- coverage.py: 1471, last pushed 2 days ago -->
-<!-- River: 1296, last pushed 0 days ago -->
-<!-- PyAV: 1142, last pushed 13 days ago -->
-<!-- Dependency Injector: 1070, last pushed 0 days ago -->
-<!-- PyTables: 1001, last pushed 6 days ago -->
-<!-- ruptures: 589, last pushed 3 days ago -->
-<!-- aioquic: 571, last pushed 78 days ago -->
-<!-- google neuroglancer: 555, last pushed 0 days ago -->
-<!-- AutoPy: 517, last pushed 134 days ago -->
-<!-- pikepdf: 517, last pushed 5 days ago -->
-<!-- Parselmouth: 450, last pushed 1 days ago -->
-<!-- python-rapidjson: 410, last pushed 39 days ago -->
-<!-- Rtree: 387, last pushed 28 days ago -->
-<!-- KDEpy: 235, last pushed 37 days ago -->
-<!-- cyvcf2: 233, last pushed 0 days ago -->
-<!-- pybind11 cmake_example: 226, last pushed 35 days ago -->
-<!-- pybind11 python_example: 224, last pushed 73 days ago -->
-<!-- dd-trace-py: 206, last pushed 0 days ago -->
-<!-- iminuit: 166, last pushed 25 days ago -->
-<!-- jq.py: 140, last pushed 102 days ago -->
-<!-- matrixprofile: 124, last pushed 2 days ago -->
-<!-- CTranslate2: 123, last pushed 0 days ago -->
-<!-- Tokenizer: 115, last pushed 3 days ago -->
-<!-- bx-python: 95, last pushed 30 days ago -->
-<!-- boost-histogram: 66, last pushed 0 days ago -->
-<!-- pybase64: 54, last pushed 0 days ago -->
-<!-- TgCrypto: 51, last pushed 65 days ago -->
-<!-- etebase-py: 40, last pushed 17 days ago -->
-<!-- pyjet: 27, last pushed 3 days ago -->
-<!-- numpythia: 24, last pushed 9 days ago -->
-<!-- fathon: 20, last pushed 4 days ago -->
-<!-- pyinstrument_cext: 10, last pushed 57 days ago -->
-<!-- Imagecodecs (fork): 10, last pushed 7 days ago -->
-<!-- xmlstarlet: 7, last pushed 2 days ago -->
-<!-- pybind11 scikit_build_example: 2, last pushed 18 days ago -->
+<!-- scikit-learn: 44749, last pushed 0 days ago -->
+<!-- Matplotlib: 13218, last pushed 0 days ago -->
+<!-- MyPy: 10122, last pushed 0 days ago -->
+<!-- psutil: 7128, last pushed 7 days ago -->
+<!-- scikit-image: 4220, last pushed 0 days ago -->
+<!-- twisted-iocpsupport: 4184, last pushed 0 days ago -->
+<!-- websockets: 3217, last pushed 13 days ago -->
+<!-- pyzmq: 2707, last pushed 13 days ago -->
+<!-- aiortc: 2244, last pushed 0 days ago -->
+<!-- numexpr: 1548, last pushed 0 days ago -->
+<!-- coverage.py: 1515, last pushed 1 days ago -->
+<!-- h5py: 1485, last pushed 0 days ago -->
+<!-- River: 1428, last pushed 0 days ago -->
+<!-- PyAV: 1182, last pushed 2 days ago -->
+<!-- Dependency Injector: 1163, last pushed 0 days ago -->
+<!-- PyTables: 1005, last pushed 18 days ago -->
+<!-- ruptures: 637, last pushed 1 days ago -->
+<!-- aioquic: 587, last pushed 15 days ago -->
+<!-- google neuroglancer: 568, last pushed 5 days ago -->
+<!-- pikepdf: 548, last pushed 0 days ago -->
+<!-- AutoPy: 519, last pushed 175 days ago -->
+<!-- Parselmouth: 471, last pushed 0 days ago -->
+<!-- python-rapidjson: 415, last pushed 80 days ago -->
+<!-- Rtree: 388, last pushed 69 days ago -->
+<!-- python-snappy: 386, last pushed 6 days ago -->
+<!-- markupsafe: 365, last pushed 2 days ago -->
+<!-- KDEpy: 242, last pushed 16 days ago -->
+<!-- cyvcf2: 242, last pushed 17 days ago -->
+<!-- pybind11 cmake_example: 239, last pushed 77 days ago -->
+<!-- pybind11 python_example: 235, last pushed 22 days ago -->
+<!-- sourmash: 235, last pushed 0 days ago -->
+<!-- dd-trace-py: 217, last pushed 0 days ago -->
+<!-- iminuit: 172, last pushed 20 days ago -->
+<!-- jq.py: 147, last pushed 7 days ago -->
+<!-- time-machine: 139, last pushed 4 days ago -->
+<!-- matrixprofile: 138, last pushed 36 days ago -->
+<!-- CTranslate2: 133, last pushed 0 days ago -->
+<!-- Tokenizer: 126, last pushed 0 days ago -->
+<!-- bx-python: 97, last pushed 2 days ago -->
+<!-- boost-histogram: 69, last pushed 0 days ago -->
+<!-- pybase64: 56, last pushed 1 days ago -->
+<!-- TgCrypto: 52, last pushed 106 days ago -->
+<!-- etebase-py: 46, last pushed 58 days ago -->
+<!-- pyjet: 27, last pushed 7 days ago -->
+<!-- numpythia: 25, last pushed 7 days ago -->
+<!-- fathon: 22, last pushed 31 days ago -->
+<!-- Imagecodecs (fork): 16, last pushed 4 days ago -->
+<!-- pyinstrument_cext: 10, last pushed 19 days ago -->
+<!-- polaroid: 9, last pushed 0 days ago -->
+<!-- xmlstarlet: 7, last pushed 1 days ago -->
+<!-- pybind11 scikit_build_example: 4, last pushed 40 days ago -->

 <!-- END bin/projects.py -->

@@ -303,6 +325,72 @@ Changelog

 <!--changelog-start-->

+### v1.11.0
+
+- 📚 Lots of docs improvements! (#650, #623, #616, #609, #606)
+- 🐛 Fix nuget "Package is not found" error on Windows. (#653)
+- ⚠️ cibuildwheel will no longer build Windows 2.7 wheels, unless you specify a custom toolchain using `DISTUTILS_USE_SDK=1` and `MSSdk=1`. This is because Microsoft have stopped distributing Visual C++ Compiler for Python 2.7. See [this FAQ entry](https://cibuildwheel.readthedocs.io/en/stable/faq/#windows-and-python-27) for more details. (#649)
+- 🐛 Fix crash on Windows due to missing `which` command (#641).
+
+### v1.10.0
+
+_22 Feb 2021_
+
+- ✨ Added `manylinux_2_24` support. To use these new Debian-based manylinux
+  images, set your [manylinux image](https://cibuildwheel.readthedocs.io/en/stable/options/#manylinux-image)
+  options to `manylinux_2_24`.
+- 🛠 On macOS, we now set `MACOSX_DEPLOYMENT_TARGET` in before running
+  `CIBW_BEFORE_ALL`. This is useful when using `CIBW_BEFORE_ALL` to build a
+  shared library.
+- 🛠 An empty `CIBW_BUILD` option is now the same as being unset i.e, `*`.
+  This makes some build matrix configuration easier. (#588)
+- 📚 Neatened up documentation - added tabs to a few places (#576), fixed some
+  formatting issues.
+
+### v1.9.0
+
+_5 February 2021_
+
+- 🌟 Added support for Apple Silicon wheels on macOS! You can now
+  cross-compile `universal2` and `arm64` wheels on your existing macOS Intel
+  runners, by setting
+  [CIBW_ARCHS_MACOS](https://cibuildwheel.readthedocs.io/en/stable/options/#archs).
+  Xcode 12.2 or later is required, but you don't need macOS 11.0 - you can
+  still build on macOS 10.15. See
+  [this FAQ entry](https://cibuildwheel.readthedocs.io/en/stable/faq/#apple-silicon)
+  for more information. (#484)
+- 🌟 Added auto-detection of your package's Python compatibility, via declared
+   [`requires-python`](https://www.python.org/dev/peps/pep-0621/#requires-python)
+  in your `pyproject.toml`, or
+  [`python_requires`](https://packaging.python.org/guides/distributing-packages-using-setuptools/#python-requires)
+  in `setup.cfg` or `setup.py`. If your project has these set, cibuildwheel
+  will automatically skip builds on versions of Python that your package
+  doesn't support. Hopefully this makes the first-run experience of
+  cibuildwheel a bit easier. If you need to override this for any reason,
+  look at [`CIBW_PROJECT_REQUIRES_PYTHON`](https://cibuildwheel.readthedocs.io/en/stable/options/#requires-python).
+  (#536)
+- 🌟 cibuildwheel can now be invoked as a native GitHub Action! You can now
+  invoke cibuildwheel in a GHA build step like:
+
+  ```yaml
+  - name: Build wheels
+    uses: joerick/cibuildwheel@version # e.g. v1.9.0
+    with:
+      output-dir: wheelhouse
+    # env:
+    #   CIBW_SOME_OPTION: value
+  ```
+
+  This saves a bit of boilerplate, and you can [use Dependabot to keep the
+  pinned version up-to-date](https://cibuildwheel.readthedocs.io/en/stable/faq/#automatic-updates).
+
+- ✨ Added `auto64` and `auto32` shortcuts to the
+  [CIBW_ARCHS](https://cibuildwheel.readthedocs.io/en/stable/options/#archs)
+  option. (#553)
+- ✨ cibuildwheel now prints a list of the wheels built at the end of each
+  run. (#570)
+- 📚 Lots of minor docs improvements.
+
 ### 1.8.0

 _22 January 2021_
@@ -310,9 +398,9 @@ _22 January 2021_
 - 🌟 Added support for emulated builds! You can now build manylinux wheels on
  ARM64`aarch64`, as well as `ppc64le` and 's390x'. To build under emulation,
  register QEMU via binfmt_misc and set the
-  [`CIBW_ARCHS_LINUX`](https://cibuildwheel.readthedocs.io/en/latest/options/#archs)
+  [`CIBW_ARCHS_LINUX`](https://cibuildwheel.readthedocs.io/en/stable/options/#archs)
  option to the architectures you want to run. See
-  [this FAQ entry](https://cibuildwheel.readthedocs.io/en/latest/faq/#emulation)
+  [this FAQ entry](https://cibuildwheel.readthedocs.io/en/stable/faq/#emulation)
  for more information. (#482)
 - ✨ Added `CIBW_TEST_SKIP` option. This allows you to choose certain builds
  whose tests you'd like to skip. This might be useful when running a slow
@@ -336,7 +424,7 @@ _1 January 2021_

 - 🛠 Added a patch for Pypy to ensure header files are available for building
  in a virtualenv. (#502)
- 🛠 Some preparatory work towards using cibuildwheel as a Github Action.
+- 🛠 Some preparatory work towards using cibuildwheel as a GitHub Action.
  Check out
  [the FAQ](https://cibuildwheel.readthedocs.io/en/stable/faq/#option-1-github-action)
  for information on how to use it. We'll be fully updating the docs to this
@@ -348,7 +436,7 @@ _21 December 2020_

 - 🛠 Update dependencies, notably wheel==0.36.2 and pip==20.3.3, and CPython to
  their latest bugfix releases (#489)
- 📚 Switch to a Github example in the README (#479)
+- 📚 Switch to a GitHub example in the README (#479)
 - 📚 Create Working Examples table, with many projects that use cibuildwheel (#474)
 - 📚 Import Working Examples table and Changelog to docs

@@ -410,6 +498,7 @@ _9 September 2020_
  [still on Python 3.9b3](https://github.com/pypa/manylinux/issues/758), not a
  release candidate. We'd advise holding off on distributing 3.9 ppc64le wheels
  until a subsequent version of cibuildwheel.
+
 - 🌟 Add Gitlab CI support. Gitlab CI can now build Linux wheels, using
  cibuildwheel. (#419)
 - 🐛 Fix a bug that causes pyproject.toml dependencies to fail to install on
@@ -453,7 +542,7 @@ _8 July 2020_
 _25 June 2020_

 - 🐛 Fix "OSError: [WinError 17] The system cannot move the file to a different
-  disk drive" on Github Actions (#388, #389)
+  disk drive" on GitHub Actions (#388, #389)

 ### 1.5.0

@@ -467,7 +556,7 @@ _24 June 2020_
  (#360, #358)
 - ✨ Added workaround to allow Python 3.5 on Windows to pull dependencies from
  pyproject.toml. (#358)
- 📚 Improved Github Actions examples and docs (#354, #362)
+- 📚 Improved GitHub Actions examples and docs (#354, #362)
 - 🐛 Ensure pip wheel uses the specified package, and doesn't build a wheel
  from PyPI (#369)
 - 🛠 Internal changes: using pathlib.Path, precommit hooks, testing
@@ -507,6 +596,7 @@ _2 May 2020_
  options - if you always want to use the latest toolchain, you can still do
  that, or you can specify your own pip constraints file and manylinux image.
  (#256)
+
 - ✨ Added `package_dir` command line option, meaning we now support building
  a package that lives in a subdirectory and pulls in files from the wider
  project. See [the `package_dir` option help](https://cibuildwheel.readthedocs.io/en/stable/options/#command-line-options)
@@ -517,6 +607,7 @@ _2 May 2020_
  will be copied into the Docker container. If your builds are slower on this
  version, that's likely the reason. `cd` to your project and then call
  `cibuildwheel` from there. (#319, #295)
+
 - 🛠 On macOS, we make `MACOSX_DEPLOYMENT_TARGET` default to `10.9` if it's
  not set. This should make things more consistent between Python versions.
 - 🛠 Dependency updates - CPython 3.7.7, CPython 2.7.18, Pypy 7.3.1.
@@ -525,7 +616,7 @@ _2 May 2020_

 _12 March 2020_

- 🌟 Add support for building on Github Actions! Check out the
+- 🌟 Add support for building on GitHub Actions! Check out the
  [docs](https://cibuildwheel.readthedocs.io/en/stable/setup/#github-actions)
  for information on how to set it up. (#194)
 - ✨ Add the `CIBW_BEFORE_TEST` option, which lets you run a command to
@@ -26,8 +26,6 @@ jobs:
    - task: UsePythonVersion@0
      inputs:
        versionSpec: '3.6'
-    - script: choco install vcpython27 -f -y
-      displayName: Install Visual C++ for Python 2.7
    - bash: |
        python -m pip install -e ".[dev]" pytest-azurepipelines
        python ./bin/run_tests.py
@@ -39,8 +37,6 @@ jobs:
    - task: UsePythonVersion@0
      inputs:
        versionSpec: '3.8'
-    - script: choco install vcpython27 -f -y
-      displayName: Install Visual C++ for Python 2.7
    - bash: |
        python -m pip install -e ".[dev]" pytest-azurepipelines
        python ./bin/run_tests.py
@@ -1,6 +1,8 @@
 #!/usr/bin/env python3


+from __future__ import annotations
+
 import glob
 import os
 import subprocess
@@ -19,29 +21,32 @@ config = [
    ('cibuildwheel/__init__.py', "__version__ = '{}'"),
    ('docs/faq.md', "cibuildwheel=={}"),
    ('docs/faq.md', "cibuildwheel@v{}"),
-    ('docs/setup.md', "cibuildwheel@v{}"),
+    ('docs/setup.md', "cibuildwheel=={}"),
    ('examples/*', "cibuildwheel=={}"),
+    ('examples/*', "cibuildwheel@v{}"),
    ('setup.cfg', "version = {}"),
 ]

+RED = "\u001b[31m"
+GREEN = "\u001b[32m"
+OFF = "\u001b[0m"
+

-# This file requires Python 3.7
-# Setting -> None will cause MyPy to notice this.
@click.command()
-def bump_version():
+def bump_version() -> None:
    current_version = cibuildwheel.__version__

    try:
        commit_date_str = subprocess.run([
            'git',
-            'show', '-s', '--pretty=format:%ci',
-            f'v{current_version}^{{commit}}'
+            'show', '--no-patch', '--pretty=format:%ci',
+            f'v{current_version}^{{commit}}',
        ], check=True, capture_output=True, encoding='utf8').stdout
-        commit_date_parts = commit_date_str.split(' ')
+        cd_date, cd_time, cd_tz = commit_date_str.split(' ')
+
+        url_opts = urllib.parse.urlencode({'q': f'is:pr merged:>{cd_date}T{cd_time}{cd_tz}'})
+        url = f'https://github.com/joerick/cibuildwheel/pulls?{url_opts}'

-        url = 'https://github.com/joerick/cibuildwheel/pulls?' + urllib.parse.urlencode({
-            'q': f'is:pr merged:>{commit_date_parts[0]}T{commit_date_parts[1]}{commit_date_parts[2]}',
-        })
        print(f'PRs merged since last release:\n  {url}')
        print()
    except subprocess.CalledProcessError as e:
@@ -55,8 +60,10 @@ def bump_version():
        print('error: Uncommitted changes detected.')
        sys.exit(1)

+    # fmt: off
    print(              'Current version:', current_version)  # noqa
    new_version = input('    New version: ').strip()
+    # fmt: on

    try:
        Version(new_version)
@@ -71,7 +78,7 @@ def bump_version():
        paths = [Path(p) for p in glob.glob(path_pattern)]

        if not paths:
-            print(f'error: Pattern {path_pattern} didn’t match any files')
+            print(f"error: Pattern {path_pattern} didn't match any files")
            sys.exit(1)

        find_pattern = version_pattern.format(current_version)
@@ -83,11 +90,11 @@ def bump_version():
            if find_pattern in contents:
                found_at_least_one_file_needing_update = True
                actions.append(
-                    (path, find_pattern, replace_pattern)
+                    (path, find_pattern, replace_pattern,)
                )

        if not found_at_least_one_file_needing_update:
-            print(f'error: Didn’t find any occurrences of “{find_pattern}” in “{path_pattern}”')
+            print(f'''error: Didn't find any occurrences of "{find_pattern}" in "{path_pattern}"''')
            sys.exit(1)

    print()
@@ -95,10 +102,8 @@ def bump_version():
    print()

    for action in actions:
-        print('{}  {red}{}{off} → {green}{}{off}'.format(
-            *action,
-            red="\u001b[31m", green="\u001b[32m", off="\u001b[0m"
-        ))
+        path, find, replace = action
+        print(f'{path}  {RED}{find}{OFF} → {GREEN}{replace}{OFF}')

    print(f'Then commit, and tag as v{new_version}')

@@ -122,21 +127,20 @@ def bump_version():

    subprocess.run([
        'git', 'commit',
-        '-a',
-        '-m', f'Bump version: v{new_version}'
+        '--all',
+        f"--message='Bump version: v{new_version}'",
    ], check=True)

    subprocess.run([
        'git', 'tag',
-        '-a',
-        '-m', f'v{new_version}',
-        f'v{new_version}'
+        '--annotate',
+        f"--message='v{new_version}'",
+        f'v{new_version}',
    ], check=True)

    print('Done.')


 if __name__ == '__main__':
-    os.chdir(os.path.dirname(__file__))
-    os.chdir('..')
+    os.chdir(Path(__file__).parent.parent.resolve())
    bump_version()
@@ -0,0 +1,110 @@
+#!/usr/bin/env python3
+from __future__ import annotations
+
+import ast
+from pathlib import Path
+from typing import Iterator
+
+import click
+import yaml
+from ghapi.core import GhApi, HTTP404NotFoundError  # type: ignore
+from rich import print
+
+from cibuildwheel.projectfiles import Analyzer
+
+DIR = Path(__file__).parent.resolve()
+
+
+def parse(contents: str) -> str | None:
+    try:
+        tree = ast.parse(contents)
+        analyzer = Analyzer()
+        analyzer.visit(tree)
+        return analyzer.requires_python or ""
+    except Exception:
+        return None
+
+
+def check_repo(name: str, contents: str) -> str:
+    s = f"  {name}: "
+    if name == "setup.py":
+        if "python_requires" not in contents:
+            s += "❌"
+        res = parse(contents)
+        if res is None:
+            s += "⚠️ "
+        elif res:
+            s += "✅ " + res
+        elif "python_requires" in contents:
+            s += "☑️"
+
+    elif name == "setup.cfg":
+        s += "✅" if "python_requires" in contents else "❌"
+    else:
+        s += "✅" if "requires-python" in contents else "❌"
+
+    return s
+
+
+class MaybeRemote:
+    def __init__(self, cached_file: Path | str, *, online: bool) -> None:
+        self.online = online
+        if self.online:
+            self.contents: dict[str, dict[str, str | None]] = {
+                "setup.py": {},
+                "setup.cfg": {},
+                "pyproject.toml": {},
+            }
+        else:
+            with open(cached_file) as f:
+                self.contents = yaml.safe_load(f)
+
+    def get(self, repo: str, filename: str) -> str | None:
+        if self.online:
+            try:
+                self.contents[filename][repo] = (
+                    GhApi(*repo.split("/")).get_content(filename).decode()
+                )
+            except HTTP404NotFoundError:
+                self.contents[filename][repo] = None
+            return self.contents[filename][repo]
+        elif repo in self.contents[filename]:
+            return self.contents[filename][repo]
+        else:
+            raise RuntimeError(
+                f"Trying to access {repo}:{filename} and not in cache, rebuild cache"
+            )
+
+    def save(self, filename: Path | str) -> None:
+        with open(filename, "w") as f:
+            yaml.safe_dump(self.contents, f, default_flow_style=False)
+
+    def on_each(self, repos: list[str]) -> Iterator[tuple[str, str, str | None]]:
+        for repo in repos:
+            print(f"[bold]{repo}:")
+            for filename in sorted(self.contents, reverse=True):
+                yield repo, filename, self.get(repo, filename)
+
+
+@click.command()
+@click.option("--online", is_flag=True, help="Remember to set GITHUB_TOKEN")
+def main(online: bool) -> None:
+    with open(DIR / "../docs/data/projects.yml") as f:
+        known = yaml.safe_load(f)
+
+    repos = [x["gh"] for x in known]
+
+    ghinfo = MaybeRemote("all_known_setup.yaml", online=online)
+
+    for _, filename, contents in ghinfo.on_each(repos):
+        if contents is None:
+            print(f"[red]  {filename}: Not found")
+        else:
+            print(check_repo(filename, contents))
+
+    if online:
+        ghinfo.save("all_known_setup.yaml")
+
+
+if __name__ == "__main__":
+    main()
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3

+from __future__ import annotations
+
 import os
 import sys
 import textwrap
@@ -49,17 +51,18 @@ def main():
            return

        shell('git commit -a -m "Update dependencies"', check=True)
-        run(
-            [
-                'gh', 'pr', 'create',
-                '--repo', 'joerick/cibuildwheel',
-                '--base', 'master',
-                '--title', 'Update dependencies',
-                '--body', textwrap.dedent(f'''
+        body = textwrap.dedent(f'''
                    Update the versions of our dependencies.

                    PR generated by `{os.path.basename(__file__)}`.
                ''')
+        run(
+            [
+                'gh', 'pr', 'create',
+                '--repo=joerick/cibuildwheel',
+                '--base=master',
+                "--title='Update dependencies'",
+                f"--body='{body}'",
            ],
            check=True
        )
@@ -9,14 +9,17 @@ Suggested usage:
    git diff
 """

+from __future__ import annotations
+
 import builtins
 import functools
+import textwrap
 import urllib.request
 import xml.dom.minidom
 from datetime import datetime
 from io import StringIO
 from pathlib import Path
-from typing import Any, Dict, List, Optional, TextIO
+from typing import Any, TextIO

 import click
 import yaml
@@ -38,7 +41,7 @@ ICONS = (
 class Project:
    NAME: int = 0

-    def __init__(self, config: Dict[str, Any], github: Optional[Github] = None):
+    def __init__(self, config: dict[str, Any], github: Github | None = None):
        try:
            self.name: str = config["name"]
            self.gh: str = config["gh"]
@@ -48,8 +51,8 @@ class Project:

        self.stars_repo: str = config.get("stars", self.gh)
        self.notes: str = config.get("notes", "")
-        self.ci: List[str] = config.get("ci", [])
-        self.os: List[str] = config.get("os", [])
+        self.ci: list[str] = config.get("ci", [])
+        self.os: list[str] = config.get("os", [])

        self.online = github is not None
        if github is not None:
@@ -72,7 +75,7 @@ class Project:
        name_len = len(self.name) + 4
        self.__class__.NAME = max(self.__class__.NAME, name_len)

-    def __lt__(self, other: "Project") -> bool:
+    def __lt__(self, other: Project) -> bool:
        if self.online:
            return self.num_stars < other.num_stars
        else:
@@ -80,10 +83,9 @@ class Project:

    @classmethod
    def header(cls) -> str:
-        return (
-            f"| {'Name':{cls.NAME}} | CI | OS | Notes |\n"
-            f"|{'':-^{cls.NAME+2  }}|----|----|:------|"
-        )
+        return textwrap.dedent(f"""\
+                | {'Name':{cls.NAME}} | CI | OS | Notes |
+                |{'':-^{cls.NAME+2  }}|----|----|:------|""")

    @property
    def namelink(self) -> str:
@@ -140,7 +142,7 @@ def path_for_icon(icon_name: str) -> Path:


 def str_projects(
-    config: List[Dict[str, Any]], *, online: bool = True, auth: Optional[str] = None
+    config: list[dict[str, Any]], *, online: bool = True, auth: str | None = None,
 ) -> str:
    io = StringIO()
    print = functools.partial(builtins.print, file=io)
@@ -178,7 +180,7 @@ def str_projects(
@click.option("--auth", help="GitHub authentication token")
@click.option("--readme", type=click.File("r+"), help="Modify a readme file if given")
 def projects(
-    input: TextIO, online: bool, auth: Optional[str], readme: Optional[TextIO]
+    input: TextIO, online: bool, auth: str | None, readme: TextIO | None
 ) -> None:
    config = yaml.safe_load(input)
    output = str_projects(config, online=online, auth=auth)
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3

+from __future__ import annotations
+
 import os
 import shutil
 import sys
@@ -123,13 +125,14 @@ def run_example_ci_configs(config_files=None):
            shutil.copyfile(src_config_file, dst_config_file)

        run(['git', 'add', example_project], check=True)
-        run(['git', 'commit', '--no-verify', '-m', textwrap.dedent(f'''
+        message = textwrap.dedent(f'''
            Test example minimal configs

            Testing files: {config_files}
            Generated from branch: {previous_branch}
            Time: {timestamp}
-        ''')], check=True)
+            ''')
+        run(['git', 'commit', '--no-verify', '--message', message], check=True)
        shell(f'git subtree --prefix={example_project} push origin {branch_name}', check=True)

        print('---')
@@ -14,7 +14,7 @@ if __name__ == '__main__':
    # run the docker unit tests only on Linux
    if sys.platform.startswith('linux'):
        unit_test_args += ['--run-docker']
-    subprocess.check_call(unit_test_args)
+    subprocess.run(unit_test_args, check=True)

    # run the integration tests
-    subprocess.check_call([sys.executable, '-m', 'pytest', '-x', '--durations', '0', '--timeout=1200', 'test'])
+    subprocess.run([sys.executable, '-m', 'pytest', '-x', '--durations', '0', '--timeout=2400', 'test'], check=True)
@@ -1,5 +1,7 @@
 #!/usr/bin/env python3

+from __future__ import annotations
+
 import argparse
 import os
 import subprocess
@@ -22,4 +24,4 @@ if __name__ == '__main__':
        options.project_python_path, project_dir
    ], check=True)

-    sys.exit(subprocess.run(['cibuildwheel'], cwd=project_dir).returncode)
+    sys.exit(subprocess.run([sys.executable, '-m', 'cibuildwheel'], cwd=project_dir).returncode)
@@ -1,11 +1,12 @@
 #!/usr/bin/env python3
+from __future__ import annotations

 import configparser
 import os
 import shutil
 import subprocess
 import sys
-from collections import namedtuple
+from typing import NamedTuple

 import requests

@@ -20,20 +21,21 @@ PYTHON_VERSIONS = ['27', '35', '36', '37', '38', '39']

 if '--no-docker' in sys.argv:
    for python_version in PYTHON_VERSIONS:
-        subprocess.check_call([
+        subprocess.run([
            f'./env{python_version}/bin/pip-compile',
            '--allow-unsafe',
            '--upgrade',
            'cibuildwheel/resources/constraints.in',
-            '--output-file', f'cibuildwheel/resources/constraints-python{python_version}.txt'
-        ])
+            '--output-file=cibuildwheel/resources/constraints-python{python_version}.txt',
+        ], check=True)
 else:
-    image_runner = 'quay.io/pypa/manylinux2010_x86_64:latest'
-    subprocess.check_call(['docker', 'pull', image_runner])
+    # latest manylinux2010 image with cpython 2.7 support
+    image_runner = 'quay.io/pypa/manylinux2010_x86_64:2021-02-06-3d322a5'
+    subprocess.run(['docker', 'pull', image_runner], check=True)
    for python_version in PYTHON_VERSIONS:
        abi_flags = '' if int(python_version) >= 38 else 'm'
        python_path = f'/opt/python/cp{python_version}-cp{python_version}{abi_flags}/bin/'
-        subprocess.check_call([
+        subprocess.run([
            'docker', 'run', '--rm',
            '-e', 'CUSTOM_COMPILE_COMMAND',
            '-v', f'{os.getcwd()}:/volume',
@@ -43,37 +45,52 @@ else:
            f'{python_path}pip-compile --allow-unsafe --upgrade '
            'cibuildwheel/resources/constraints.in '
            f'--output-file cibuildwheel/resources/constraints-python{python_version}.txt'
-        ])
+        ], check=True)

 # default constraints.txt
-shutil.copyfile(f'cibuildwheel/resources/constraints-python{PYTHON_VERSIONS[-1]}.txt', 'cibuildwheel/resources/constraints.txt')
+shutil.copyfile(f'cibuildwheel/resources/constraints-python{PYTHON_VERSIONS[-1]}.txt', 'cibuildwheel/resources/constraints.txt',)
+
+
+class Image(NamedTuple):
+    manylinux_version: str
+    platform: str
+    image_name: str
+    tag: str | None

-Image = namedtuple('Image', [
-    'manylinux_version',
-    'platform',
-    'image_name',
-])

 images = [
-    Image('manylinux1', 'x86_64', 'quay.io/pypa/manylinux1_x86_64'),
-    Image('manylinux1', 'i686', 'quay.io/pypa/manylinux1_i686'),
+    Image('manylinux1', 'x86_64', 'quay.io/pypa/manylinux1_x86_64', None),
+    Image('manylinux1', 'i686', 'quay.io/pypa/manylinux1_i686', None),

-    Image('manylinux2010', 'x86_64', 'quay.io/pypa/manylinux2010_x86_64'),
-    Image('manylinux2010', 'i686', 'quay.io/pypa/manylinux2010_i686'),
-    Image('manylinux2010', 'pypy_x86_64', 'pypywheels/manylinux2010-pypy_x86_64'),
+    # Images for manylinux2010 are pinned to the latest tag supporting cp27
+    Image('manylinux2010', 'x86_64', 'quay.io/pypa/manylinux2010_x86_64', '2021-02-06-3d322a5'),
+    Image('manylinux2010', 'i686', 'quay.io/pypa/manylinux2010_i686', '2021-02-06-3d322a5'),

-    Image('manylinux2014', 'x86_64', 'quay.io/pypa/manylinux2014_x86_64'),
-    Image('manylinux2014', 'i686', 'quay.io/pypa/manylinux2014_i686'),
-    Image('manylinux2014', 'aarch64', 'quay.io/pypa/manylinux2014_aarch64'),
-    Image('manylinux2014', 'ppc64le', 'quay.io/pypa/manylinux2014_ppc64le'),
-    Image('manylinux2014', 's390x', 'quay.io/pypa/manylinux2014_s390x'),
+    Image('manylinux2010', 'pypy_x86_64', 'pypywheels/manylinux2010-pypy_x86_64', None),
+
+    # 2014 images
+    Image('manylinux2014', 'x86_64', 'quay.io/pypa/manylinux2014_x86_64', None),
+    Image('manylinux2014', 'i686', 'quay.io/pypa/manylinux2014_i686', None),
+    Image('manylinux2014', 'aarch64', 'quay.io/pypa/manylinux2014_aarch64', None),
+    Image('manylinux2014', 'ppc64le', 'quay.io/pypa/manylinux2014_ppc64le', None),
+    Image('manylinux2014', 's390x', 'quay.io/pypa/manylinux2014_s390x', None),
+
+    # 2_24 images
+    Image('manylinux_2_24', 'x86_64', 'quay.io/pypa/manylinux_2_24_x86_64', None),
+    Image('manylinux_2_24', 'i686', 'quay.io/pypa/manylinux_2_24_i686', None),
+    Image('manylinux_2_24', 'aarch64', 'quay.io/pypa/manylinux_2_24_aarch64', None),
+    Image('manylinux_2_24', 'ppc64le', 'quay.io/pypa/manylinux_2_24_ppc64le', None),
+    Image('manylinux_2_24', 's390x', 'quay.io/pypa/manylinux_2_24_s390x', None),
 ]

 config = configparser.ConfigParser()

 for image in images:
    # get the tag name whose digest matches 'latest'
-    if image.image_name.startswith('quay.io/'):
+    if image.tag is not None:
+        # image has been pinned, do not update
+        tag_name = image.tag
+    elif image.image_name.startswith('quay.io/'):
        _, _, repository_name = image.image_name.partition('/')
        response = requests.get(
            f'https://quay.io/api/v1/repository/{repository_name}?includeTags=true'
@@ -1,10 +1,12 @@
 #!/usr/bin/env python3

+from __future__ import annotations
+
 import copy
 import difflib
 import logging
 from pathlib import Path
-from typing import Dict, Optional, Union
+from typing import Union

 import click
 import requests
@@ -80,7 +82,7 @@ class WindowsVersions:
        versions = (Version(v) for v in cp_info["versions"])
        self.versions = sorted(v for v in versions if not v.is_devrelease)

-    def update_version_windows(self, spec: Specifier) -> Optional[ConfigWinCP]:
+    def update_version_windows(self, spec: Specifier) -> ConfigWinCP | None:
        versions = sorted(v for v in self.versions if spec.contains(v))
        if not all(v.is_prerelease for v in versions):
            versions = [v for v in versions if not v.is_prerelease]
@@ -91,12 +93,11 @@ class WindowsVersions:

        version = versions[-1]
        identifier = f"cp{version.major}{version.minor}-{self.arch}"
-        result = ConfigWinCP(
+        return ConfigWinCP(
            identifier=identifier,
            version=str(version),
            arch=self.arch_str,
        )
-        return result


 class PyPyVersions:
@@ -164,14 +165,14 @@ class PyPyVersions:


 class CPythonVersions:
-    def __init__(self, plat_arch: str, file_ident: str) -> None:
+    def __init__(self) -> None:

        response = requests.get("https://www.python.org/api/v2/downloads/release/?is_published=true")
        response.raise_for_status()

        releases_info = response.json()

-        self.versions_dict: Dict[Version, int] = {}
+        self.versions_dict: dict[Version, int] = {}
        for release in releases_info:
            # Removing the prefix, Python 3.9 would use: release["name"].removeprefix("Python ")
            version = Version(release["name"][7:])
@@ -180,11 +181,8 @@ class CPythonVersions:
                uri = int(release["resource_uri"].rstrip("/").split("/")[-1])
                self.versions_dict[version] = uri

-        self.file_ident = file_ident
-        self.plat_arch = plat_arch
-
-    def update_version_macos(self, spec: Specifier) -> Optional[ConfigMacOS]:
-
+    def update_version_macos(self, identifier: str, spec: Specifier) -> ConfigMacOS | None:
+        file_idents = ("macos11.pkg", "macosx10.9.pkg", "macosx10.6.pkg")
        sorted_versions = sorted(v for v in self.versions_dict if spec.contains(v))

        for version in reversed(sorted_versions):
@@ -194,13 +192,14 @@ class CPythonVersions:
            response.raise_for_status()
            file_info = response.json()

-            urls = [rf["url"] for rf in file_info if self.file_ident in rf["url"]]
-            if urls:
-                return ConfigMacOS(
-                    identifier=f"cp{version.major}{version.minor}-{self.plat_arch}",
-                    version=f"{version.major}.{version.minor}",
-                    url=urls[0],
-                )
+            for file_ident in file_idents:
+                urls = [rf["url"] for rf in file_info if file_ident in rf["url"]]
+                if urls:
+                    return ConfigMacOS(
+                        identifier=identifier,
+                        version=f"{version.major}.{version.minor}",
+                        url=urls[0],
+                    )

        return None

@@ -215,25 +214,24 @@ class AllVersions:
        self.windows_64 = WindowsVersions("64")
        self.windows_pypy = PyPyVersions("32")

-        self.macos_6 = CPythonVersions(plat_arch="macosx_x86_64", file_ident="macosx10.6.pkg")
-        self.macos_9 = CPythonVersions(plat_arch="macosx_x86_64", file_ident="macosx10.9.pkg")
-        self.macos_u2 = CPythonVersions(plat_arch="macosx_universal2", file_ident="macos11.0.pkg")
+        self.macos_cpython = CPythonVersions()
        self.macos_pypy = PyPyVersions("64")

-    def update_config(self, config: Dict[str, str]) -> None:
+    def update_config(self, config: dict[str, str]) -> None:
        identifier = config["identifier"]
        version = Version(config["version"])
        spec = Specifier(f"=={version.major}.{version.minor}.*")
        log.info(f"Reading in '{identifier}' -> {spec} @ {version}")
        orig_config = copy.copy(config)
-        config_update: Optional[AnyConfig]
+        config_update: AnyConfig | None

        # We need to use ** in update due to MyPy (probably a bug)
-        if "macosx_x86_64" in identifier:
+        if "macos" in identifier:
            if identifier.startswith("pp"):
                config_update = self.macos_pypy.update_version_macos(spec)
            else:
-                config_update = self.macos_9.update_version_macos(spec) or self.macos_6.update_version_macos(spec)
+                config_update = self.macos_cpython.update_version_macos(identifier, spec)
+
            assert config_update is not None, f"MacOS {spec} not found!"
            config.update(**config_update)
        elif "win32" in identifier:
@@ -1 +1 @@
-__version__ = '1.8.0'
+__version__ = '1.11.0'
@@ -7,12 +7,16 @@ from configparser import ConfigParser
 from pathlib import Path
 from typing import Dict, List, Optional, Set, Union, overload

+from packaging.specifiers import SpecifierSet
+
 import cibuildwheel
 import cibuildwheel.linux
 import cibuildwheel.macos
+import cibuildwheel.util
 import cibuildwheel.windows
 from cibuildwheel.architecture import Architecture, allowed_architectures_check
 from cibuildwheel.environment import EnvironmentParseError, parse_environment
+from cibuildwheel.projectfiles import get_requires_python_str
 from cibuildwheel.typing import PLATFORMS, PlatformName, assert_never
 from cibuildwheel.util import (
    BuildOptions,
@@ -26,10 +30,10 @@ from cibuildwheel.util import (


@overload
-def get_option_from_environment(option_name: str, platform: Optional[str], default: str) -> str: ...  # noqa: E704
+def get_option_from_environment(option_name: str, *, platform: Optional[str] = None, default: str) -> str: ...  # noqa: E704
@overload
-def get_option_from_environment(option_name: str, platform: Optional[str] = None, default: None = None) -> Optional[str]: ...  # noqa: E704 E302
-def get_option_from_environment(option_name: str, platform: Optional[str] = None, default: Optional[str] = None) -> Optional[str]:  # noqa: E302
+def get_option_from_environment(option_name: str, *, platform: Optional[str] = None, default: None = None) -> Optional[str]: ...  # noqa: E704 E302
+def get_option_from_environment(option_name: str, *, platform: Optional[str] = None, default: Optional[str] = None) -> Optional[str]:  # noqa: E302
    '''
    Returns an option from the environment, optionally scoped by the platform.

@@ -69,19 +73,22 @@ def main() -> None:
                            Python. Default: auto.
                        ''')

+    arch_list_str = ", ".join(a.name for a in Architecture)
    parser.add_argument('--archs',
                        default=None,
-                        help='''
+                        help=f'''
                            Comma-separated list of CPU architectures to build for.
                            When set to 'auto', builds the architectures natively supported
                            on this machine. Set this option to build an architecture
                            via emulation, for example, using binfmt_misc and QEMU.
                            Default: auto.
-                            Choices: auto, native, all, {}
-                        '''.format(", ".join(a.name for a in Architecture)))
+                            Choices: auto, auto64, auto32, native, all, {arch_list_str}
+                        ''')
+
    parser.add_argument('--output-dir',
                        default=os.environ.get('CIBW_OUTPUT_DIR', 'wheelhouse'),
                        help='Destination folder for the wheels.')
+
    parser.add_argument('package_dir',
                        default='.',
                        nargs='?',
@@ -95,6 +102,7 @@ def main() -> None:
    parser.add_argument('--print-build-identifiers',
                        action='store_true',
                        help='Print the build identifiers matched by the current invocation and exit.')
+
    parser.add_argument('--allow-empty',
                        action='store_true',
                        help='Do not report an error code if the build does not match any wheels.')
@@ -137,13 +145,14 @@ def main() -> None:
    if platform == 'linux':
        repair_command_default = 'auditwheel repair -w {dest_dir} {wheel}'
    elif platform == 'macos':
-        repair_command_default = 'delocate-listdeps {wheel} && delocate-wheel --require-archs x86_64 -w {dest_dir} {wheel}'
+        repair_command_default = 'delocate-listdeps {wheel} && delocate-wheel --require-archs {delocate_archs} -w {dest_dir} {wheel}'
    elif platform == 'windows':
        repair_command_default = ''
    else:
        assert_never(platform)

-    build_config, skip_config = os.environ.get('CIBW_BUILD', '*'), os.environ.get('CIBW_SKIP', '')
+    build_config = os.environ.get('CIBW_BUILD') or '*'
+    skip_config = os.environ.get('CIBW_SKIP', '')
    test_skip = os.environ.get('CIBW_TEST_SKIP', '')
    environment_config = get_option_from_environment('CIBW_ENVIRONMENT', platform=platform, default='')
    before_all = get_option_from_environment('CIBW_BEFORE_ALL', platform=platform, default='')
@@ -156,7 +165,18 @@ def main() -> None:
    test_extras = get_option_from_environment('CIBW_TEST_EXTRAS', platform=platform, default='')
    build_verbosity_str = get_option_from_environment('CIBW_BUILD_VERBOSITY', platform=platform, default='')

-    build_selector = BuildSelector(build_config=build_config, skip_config=skip_config)
+    package_files = {'setup.py', 'setup.cfg', 'pyproject.toml'}
+
+    if not any(package_dir.joinpath(name).exists() for name in package_files):
+        names = ', '.join(sorted(package_files, reverse=True))
+        print(f'cibuildwheel: Could not find any of {{{names}}} at root of package', file=sys.stderr)
+        sys.exit(2)
+
+    # Passing this in as an environment variable will override pyproject.toml, setup.cfg, or setup.py
+    requires_python_str: Optional[str] = os.environ.get('CIBW_PROJECT_REQUIRES_PYTHON') or get_requires_python_str(package_dir)
+    requires_python = None if requires_python_str is None else SpecifierSet(requires_python_str)
+
+    build_selector = BuildSelector(build_config=build_config, skip_config=skip_config, requires_python=requires_python)
    test_selector = TestSelector(skip_config=test_skip)

    try:
@@ -186,15 +206,11 @@ def main() -> None:
    # This needs to be passed on to the docker container in linux.py
    os.environ['CIBUILDWHEEL'] = '1'

-    if not any((package_dir / name).exists()
-               for name in ["setup.py", "setup.cfg", "pyproject.toml"]):
-        print('cibuildwheel: Could not find setup.py, setup.cfg or pyproject.toml at root of package', file=sys.stderr)
-        sys.exit(2)
-
    if args.archs is not None:
        archs_config_str = args.archs
    else:
        archs_config_str = get_option_from_environment('CIBW_ARCHS', platform=platform, default='auto')
+
    archs = Architecture.parse_config(archs_config_str, platform=platform)

    identifiers = get_build_identifiers(platform, build_selector, archs)
@@ -271,14 +287,15 @@ def main() -> None:
    if not output_dir.exists():
        output_dir.mkdir(parents=True)

-    if platform == 'linux':
-        cibuildwheel.linux.build(build_options)
-    elif platform == 'windows':
-        cibuildwheel.windows.build(build_options)
-    elif platform == 'macos':
-        cibuildwheel.macos.build(build_options)
-    else:
-        assert_never(platform)
+    with cibuildwheel.util.print_new_wheels("\n{n} wheels produced in {m:.0f} minutes:", output_dir):
+        if platform == 'linux':
+            cibuildwheel.linux.build(build_options)
+        elif platform == 'windows':
+            cibuildwheel.windows.build(build_options)
+        elif platform == 'macos':
+            cibuildwheel.macos.build(build_options)
+        else:
+            assert_never(platform)


 def detect_obsolete_options() -> None:
@@ -334,12 +351,13 @@ def get_build_identifiers(
    python_configurations: Union[List[cibuildwheel.linux.PythonConfiguration],
                                 List[cibuildwheel.windows.PythonConfiguration],
                                 List[cibuildwheel.macos.PythonConfiguration]]
+
    if platform == 'linux':
        python_configurations = cibuildwheel.linux.get_python_configurations(build_selector, architectures)
    elif platform == 'windows':
        python_configurations = cibuildwheel.windows.get_python_configurations(build_selector, architectures)
    elif platform == 'macos':
-        python_configurations = cibuildwheel.macos.get_python_configurations(build_selector)
+        python_configurations = cibuildwheel.macos.get_python_configurations(build_selector, architectures)
    else:
        assert_never(platform)

@@ -353,9 +371,13 @@ def detect_warnings(platform: str, build_options: BuildOptions) -> List[str]:
    for option_name in ['test_command', 'before_build']:
        option_value = getattr(build_options, option_name)

-        if option_value:
-            if '{python}' in option_value or '{pip}' in option_value:
-                warnings.append(option_name + ": '{python}' and '{pip}' are no longer needed, and will be removed in a future release. Simply use 'python' or 'pip' instead.")
+        if option_value and ('{python}' in option_value or '{pip}' in option_value):
+            # Reminder: in an f-string, double braces means literal single brace
+            msg = (
+                f"{option_name}: '{{python}}' and '{{pip}}' are no longer needed, "
+                "and will be removed in a future release. Simply use 'python' or 'pip' instead."
+            )
+            warnings.append(msg)

    return warnings

@@ -4,7 +4,7 @@ import re
 from enum import Enum
 from typing import Set

-from .typing import PlatformName, assert_never
+from .typing import Literal, PlatformName, assert_never

 PRETTY_NAMES = {'linux': 'Linux', 'macos': 'macOS', 'windows': 'Windows'}

@@ -15,11 +15,17 @@ class Architecture(Enum):

    # mac/linux archs
    x86_64 = 'x86_64'
+
+    # linux archs
    i686 = 'i686'
    aarch64 = 'aarch64'
    ppc64le = 'ppc64le'
    s390x = 's390x'

+    # mac archs
+    universal2 = 'universal2'
+    arm64 = 'arm64'
+
    # windows archs
    x86 = 'x86'
    AMD64 = 'AMD64'
@@ -38,6 +44,10 @@ class Architecture(Enum):
                result.add(Architecture(platform_module.machine()))
            elif arch_str == 'all':
                result |= Architecture.all_archs(platform=platform)
+            elif arch_str == 'auto64':
+                result |= Architecture.bitness_archs(platform=platform, bitness="64")
+            elif arch_str == 'auto32':
+                result |= Architecture.bitness_archs(platform=platform, bitness="32")
            else:
                result.add(Architecture(arch_str))
        return result
@@ -46,11 +56,18 @@ class Architecture(Enum):
    def auto_archs(platform: PlatformName) -> 'Set[Architecture]':
        native_architecture = Architecture(platform_module.machine())
        result = {native_architecture}
+
        if platform == 'linux' and native_architecture == Architecture.x86_64:
            # x86_64 machines can run i686 docker containers
            result.add(Architecture.i686)
+
        if platform == 'windows' and native_architecture == Architecture.AMD64:
            result.add(Architecture.x86)
+
+        if platform == 'macos' and native_architecture == Architecture.arm64:
+            # arm64 can build and test both archs of a universal2 wheel.
+            result.add(Architecture.universal2)
+
        return result

    @staticmethod
@@ -58,12 +75,24 @@ class Architecture(Enum):
        if platform == 'linux':
            return {Architecture.x86_64, Architecture.i686, Architecture.aarch64, Architecture.ppc64le, Architecture.s390x}
        elif platform == 'macos':
-            return {Architecture.x86_64}
+            return {Architecture.x86_64, Architecture.arm64, Architecture.universal2}
        elif platform == 'windows':
            return {Architecture.x86, Architecture.AMD64}
        else:
            assert_never(platform)

+    @staticmethod
+    def bitness_archs(platform: PlatformName, bitness: Literal['64', '32']) -> 'Set[Architecture]':
+        archs_32 = {Architecture.i686, Architecture.x86}
+        auto_archs = Architecture.auto_archs(platform)
+
+        if bitness == '64':
+            return auto_archs - archs_32
+        elif bitness == '32':
+            return auto_archs & archs_32
+        else:
+            assert_never(bitness)
+

 def allowed_architectures_check(
    platform: PlatformName,
@@ -8,7 +8,7 @@ EnvironmentExecutor = Callable[[List[str], Dict[str, str]], str]


 def local_environment_executor(command: List[str], env: Dict[str, str]) -> str:
-    return subprocess.check_output(command, env=env, universal_newlines=True)
+    return subprocess.run(command, env=env, universal_newlines=True, stdout=subprocess.PIPE, check=True).stdout


 class NodeExecutionContext(NamedTuple):
@@ -58,9 +58,8 @@ def evaluate_word_node(node: bashlex.ast.node, context: NodeExecutionContext) ->

        if part_string not in value:
            raise RuntimeError(
-                'bash parse failed. part "{}" not found in "{}". Word was "{}". Full input was "{}"'.format(
-                    part_string, value, node.word, context.input,
-                )
+                f'bash parse failed. part "{part_string}" not found in "{value}". '
+                f'Word was "{node.word}". Full input was "{context.input}"'
            )

        value = value.replace(part_string, part_value, 1)
@@ -85,9 +84,7 @@ def evaluate_nodes_as_compound_command(nodes: Sequence[bashlex.ast.node], contex
        if node.kind == 'command':
            result += evaluate_command_node(node, context=context)
        elif node.kind == 'operator':
-            if node.op == ';':
-                pass
-            else:
+            if node.op != ';':
                raise ValueError(f'Unsupported bash operator: "{node.op}"')
        else:
            raise ValueError(f'Unsupported bash node in compound command: "{node.kind}"')
@@ -45,10 +45,10 @@ class DockerContainer:
        subprocess.run(
            [
                'docker', 'create',
-                '--env', 'CIBUILDWHEEL',
-                '--name', self.name,
-                '-i',
-                '-v', '/:/host',  # ignored on CircleCI
+                '--env=CIBUILDWHEEL',
+                f'--name={self.name}',
+                '--interactive',
+                '--volume=/:/host',  # ignored on CircleCI
                *cwd_args,
                self.docker_image,
                *shell_args
@@ -169,13 +169,15 @@ class DockerContainer:
        while True:
            line = self.bash_stdout.readline()

-            if line.endswith(b'%s\n' % (bytes(end_of_message, encoding='utf8'))):
+            if line.endswith(bytes(end_of_message, encoding='utf8') + b'\n'):
+                # fmt: off
                footer_offset = (
                    len(line)
                    - 1  # newline character
                    - len(end_of_message)  # delimiter
                    - 4  # 4 returncode decimals
                )
+                # fmt: on
                returncode_str = line[footer_offset:footer_offset+4]
                returncode = int(returncode_str)
                # add the last line to output, without the footer
@@ -14,11 +14,10 @@ class InlineArrayDictEncoder(toml.encoder.TomlEncoder):  # type: ignore
        self.dump_funcs[Version] = lambda v: f'"{v}"'

    def dump_sections(self, o: Dict[str, Any], sup: str) -> Any:
-        if all(isinstance(a, list) for a in o.values()):
-            val = ""
-            for k, v in o.items():
-                inner = ",\n  ".join(self.dump_inline_table(d_i).strip() for d_i in v)
-                val += f"{k} = [\n  {inner},\n]\n"
-            return val, self._dict()
-        else:
+        if not all(isinstance(a, list) for a in o.values()):
            return super().dump_sections(o, sup)
+        val = ""
+        for k, v in o.items():
+            inner = ",\n  ".join(self.dump_inline_table(d_i).strip() for d_i in v)
+            val += f"{k} = [\n  {inner},\n]\n"
+        return val, self._dict()
@@ -31,7 +31,7 @@ class PythonConfiguration(NamedTuple):

 def get_python_configurations(
    build_selector: BuildSelector,
-    architectures: Set[Architecture]
+    architectures: Set[Architecture],
 ) -> List[PythonConfiguration]:

    full_python_configs = read_python_configs('linux')
@@ -49,7 +49,8 @@ def get_python_configurations(

 def build(options: BuildOptions) -> None:
    try:
-        subprocess.check_output(['docker', '--version'])
+        # check docker is installed
+        subprocess.run(['docker', '--version'], check=True, stdout=subprocess.DEVNULL)
    except Exception:
        print('cibuildwheel: Docker not found. Docker is required to run Linux builds. '
              'If you\'re building on Travis CI, add `services: [docker]` to your .travis.yml.'
@@ -94,6 +95,7 @@ def build(options: BuildOptions) -> None:

                    env = docker.get_environment()
                    env['PATH'] = f'/opt/python/cp38-cp38/bin:{env["PATH"]}'
+                    env['PIP_DISABLE_PIP_VERSION_CHECK'] = '1'
                    env = options.environment.as_dictionary(env, executor=docker.environment_executor)

                    before_all_prepared = prepare_command(options.before_all, project=container_project_path, package=container_package_dir)
@@ -157,7 +159,7 @@ def build(options: BuildOptions) -> None:
                    docker.call([
                        'pip', 'wheel',
                        container_package_dir,
-                        '-w', built_wheel_dir,
+                        '--wheel-dir', built_wheel_dir,
                        '--no-deps',
                        *get_build_verbosity_extra_flags(options.build_verbosity)
                    ], env=env)
@@ -228,7 +230,7 @@ def build(options: BuildOptions) -> None:
                docker.copy_out(container_output_dir, options.output_dir)
                log.step_end()
        except subprocess.CalledProcessError as error:
-            log.error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
+            log.step_end_with_error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
            troubleshoot(options.package_dir, error)
            sys.exit(1)

@@ -251,5 +253,5 @@ def troubleshoot(package_dir: Path, error: Exception) -> None:
            '''), file=sys.stderr)

            print('  Files detected:')
-            print('\n'.join([f'    {f}' for f in so_files]))
+            print('\n'.join(f'    {f}' for f in so_files))
            print('')
@@ -23,6 +23,8 @@ PLATFORM_IDENTIFIER_DESCIPTIONS = {
    'win32': 'Windows 32bit',
    'win_amd64': 'Windows 64bit',
    'macosx_x86_64': 'macOS x86_64',
+    'macosx_universal2': 'macOS Universal 2 - x86_64 and arm64',
+    'macosx_arm64': 'macOS arm64 - Apple Silicon',
 }


@@ -109,15 +111,23 @@ class Logger:

            self.step_start_time = None

-    def error(self, error: Union[BaseException, str]) -> None:
+    def step_end_with_error(self, error: Union[BaseException, str]) -> None:
        self.step_end(success=False)
-        print()
+        self.error(error)

+    def warning(self, message: str) -> None:
        if self.fold_mode == 'github':
-            print(f'::error::{error}')
+            print(f'::warning::{message}\n', file=sys.stderr)
        else:
            c = self.colors
-            print(f'{c.bright_red}Error{c.end} {error}')
+            print(f'{c.yellow}Warning{c.end}: {message}\n', file=sys.stderr)
+
+    def error(self, error: Union[BaseException, str]) -> None:
+        if self.fold_mode == 'github':
+            print(f'::error::{error}\n', file=sys.stderr)
+        else:
+            c = self.colors
+            print(f'{c.bright_red}Error{c.end}: {error}\n', file=sys.stderr)

    def _start_fold_group(self, name: str) -> None:
        self._end_fold_group()
@@ -1,15 +1,18 @@
 import os
+import platform
+import re
 import shlex
 import shutil
 import subprocess
 import sys
 import tempfile
 from pathlib import Path
-from typing import Dict, List, NamedTuple, Optional, Sequence
+from typing import Any, Dict, List, NamedTuple, Optional, Sequence, Set, Tuple, cast

+from .architecture import Architecture
 from .environment import ParsedEnvironment
 from .logger import log
-from .typing import PathOrStr
+from .typing import Literal, PathOrStr
 from .util import (
    BuildOptions,
    BuildSelector,
@@ -21,17 +24,43 @@ from .util import (
    prepare_command,
    read_python_configs,
    resources_dir,
+    unwrap,
 )


-def call(args: Sequence[PathOrStr], env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None, shell: bool = False) -> int:
+def call(args: Sequence[PathOrStr], env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None, shell: bool = False) -> None:
    # print the command executing for the logs
    if shell:
        print(f'+ {args}')
    else:
        print('+ ' + ' '.join(shlex.quote(str(a)) for a in args))

-    return subprocess.check_call(args, env=env, cwd=cwd, shell=shell)
+    subprocess.run(args, env=env, cwd=cwd, shell=shell, check=True)
+
+
+def get_macos_version() -> Tuple[int, int]:
+    '''
+    Returns the macOS major/minor version, as a tuple, e.g. (10, 15) or (11, 0)
+
+    These tuples can be used in comparisons, e.g.
+        (10, 14) <= (11, 0) == True
+        (10, 14) <= (10, 16) == True
+        (11, 2) <= (11, 0) != True
+    '''
+    version_str, _, _ = platform.mac_ver()
+    version = tuple(map(int, version_str.split(".")[:2]))
+    return cast(Tuple[int, int], version)
+
+
+def get_macos_sdks() -> List[str]:
+    output = subprocess.run(
+        ['xcodebuild', '-showsdks'],
+        universal_newlines=True,
+        check=True,
+        stdout=subprocess.PIPE,
+    ).stdout
+
+    return [m.group(1) for m in re.finditer(r'-sdk (macosx\S+)', output)]


 class PythonConfiguration(NamedTuple):
@@ -40,15 +69,43 @@ class PythonConfiguration(NamedTuple):
    url: str


-def get_python_configurations(
-        build_selector: BuildSelector) -> List[PythonConfiguration]:
+def get_python_configurations(build_selector: BuildSelector,
+                              architectures: Set[Architecture]) -> List[PythonConfiguration]:

    full_python_configs = read_python_configs('macos')

    python_configurations = [PythonConfiguration(**item) for item in full_python_configs]

-    # skip builds as required
-    return [c for c in python_configurations if build_selector(c.identifier)]
+    # filter out configs that don't match any of the selected architectures
+    python_configurations = [c for c in python_configurations
+                             if any(c.identifier.endswith(a.value) for a in architectures)]
+
+    # skip builds as required by BUILD/SKIP
+    python_configurations = [c for c in python_configurations if build_selector(c.identifier)]
+
+    # When running on macOS 11 and x86_64, the reported OS is '10.16', but
+    # there is no such OS - it really means macOS 11.
+    if get_macos_version() >= (10, 16):
+        if any(c.identifier.startswith('pp') for c in python_configurations):
+            # pypy doesn't work on macOS 11 yet
+            # See https://foss.heptapod.net/pypy/pypy/-/issues/3314
+            log.warning(unwrap('''
+                PyPy is currently unsupported when building on macOS 11. To build macOS PyPy wheels,
+                build on an older OS, such as macOS 10.15. To silence this warning, deselect PyPy by
+                adding "pp*-macosx*" to your CIBW_SKIP option.
+            '''))
+            python_configurations = [c for c in python_configurations if not c.identifier.startswith('pp')]
+
+        if any(c.identifier.startswith('cp35') for c in python_configurations):
+            # CPython 3.5 doesn't work on macOS 11
+            log.warning(unwrap('''
+                CPython 3.5 is unsupported when building on macOS 11. To build CPython 3.5 wheels,
+                build on an older OS, such as macOS 10.15. To silence this warning, deselect CPython
+                3.5 by adding "cp35-macosx_x86_64" to your CIBW_SKIP option.
+            '''))
+            python_configurations = [c for c in python_configurations if not c.identifier.startswith('cp35')]
+
+    return python_configurations


 SYMLINKS_DIR = Path('/tmp/cibw_bin')
@@ -70,7 +127,7 @@ def make_symlinks(installation_bin_path: Path, python_executable: str, pip_execu


 def install_cpython(version: str, url: str) -> Path:
-    installed_system_packages = subprocess.check_output(['pkgutil', '--pkgs'], universal_newlines=True).splitlines()
+    installed_system_packages = subprocess.run(['pkgutil', '--pkgs'], universal_newlines=True, check=True, stdout=subprocess.PIPE).stdout.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}'
@@ -150,10 +207,13 @@ def setup_python(python_configuration: PythonConfiguration,
    env.pop('__PYVENV_LAUNCHER__', None)
    env = environment.as_dictionary(prev_environment=env)

+    # we version pip ourselves, so we don't care about pip version checking
+    env['PIP_DISABLE_PIP_VERSION_CHECK'] = '1'
+
    # check what version we're on
    call(['which', 'python'], env=env)
    call(['python', '--version'], env=env)
-    which_python = subprocess.check_output(['which', 'python'], env=env, universal_newlines=True).strip()
+    which_python = subprocess.run(['which', 'python'], env=env, universal_newlines=True, check=True, stdout=subprocess.PIPE).stdout.strip()
    if which_python != '/tmp/cibw_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)
@@ -163,7 +223,7 @@ def setup_python(python_configuration: PythonConfiguration,
    assert (installation_bin_path / 'pip').exists()
    call(['which', 'pip'], env=env)
    call(['pip', '--version'], env=env)
-    which_pip = subprocess.check_output(['which', 'pip'], env=env, universal_newlines=True).strip()
+    which_pip = subprocess.run(['which', 'pip'], env=env, universal_newlines=True, check=True, stdout=subprocess.PIPE).stdout.strip()
    if which_pip != '/tmp/cibw_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)
@@ -173,6 +233,9 @@ def setup_python(python_configuration: PythonConfiguration,
    # inconsistencies if it's left unset.
    env.setdefault('MACOSX_DEPLOYMENT_TARGET', '10.9')

+    config_is_arm64 = python_configuration.identifier.endswith('arm64')
+    config_is_universal2 = python_configuration.identifier.endswith('universal2')
+
    if python_configuration.version == '3.5':
        # Cross-compilation platform override - CPython 3.5 has an
        # i386/x86_64 version of Python, but we only want a x64_64 build
@@ -180,6 +243,41 @@ def setup_python(python_configuration: PythonConfiguration,
        # https://github.com/python/cpython/blob/a5ed2fe0eedefa1649aa93ee74a0bafc8e628a10/Lib/_osx_support.py#L260
        env.setdefault('ARCHFLAGS', '-arch x86_64')

+    if python_configuration.version == '3.9':
+        if python_configuration.identifier.endswith('x86_64'):
+            # even on the macos11.0 Python installer, on the x86_64 side it's
+            # compatible back to 10.9.
+            env.setdefault('_PYTHON_HOST_PLATFORM', 'macosx-10.9-x86_64')
+            env.setdefault('ARCHFLAGS', '-arch x86_64')
+        elif config_is_arm64:
+            # macOS 11 is the first OS with arm64 support, so the wheels
+            # have that as a minimum.
+            env.setdefault('_PYTHON_HOST_PLATFORM', 'macosx-11.0-arm64')
+            env.setdefault('ARCHFLAGS', '-arch arm64')
+        elif config_is_universal2:
+            if get_macos_version() < (10, 16):
+                # we can do universal2 builds on macos 10.15, but we need to
+                # set ARCHFLAGS otherwise CPython sets it to `-arch x86_64`
+                env.setdefault('ARCHFLAGS', '-arch arm64 -arch x86_64')
+
+    building_arm64 = config_is_arm64 or config_is_universal2
+    if building_arm64 and get_macos_version() < (10, 16) and 'SDKROOT' not in env:
+        # xcode 12.2 or higher can build arm64 on macos 10.15 or below, but
+        # needs the correct SDK selected.
+        sdks = get_macos_sdks()
+
+        # Different versions of Xcode contain different SDK versions...
+        # we're happy with anything newer than macOS 11.0
+        arm64_compatible_sdks = [s for s in sdks if not s.startswith('macosx10.')]
+
+        if not arm64_compatible_sdks:
+            log.warning(unwrap('''
+                    SDK for building arm64-compatible wheels not found. You need Xcode 12.2 or later
+                    to build universal2 or arm64 wheels.
+                '''))
+        else:
+            env.setdefault('SDKROOT', arm64_compatible_sdks[0])
+
    log.step('Installing build tools...')
    call(['pip', 'install', '--upgrade', 'setuptools', 'wheel', 'delocate', *dependency_constraint_flags], env=env)

@@ -195,14 +293,18 @@ def build(options: BuildOptions) -> None:
        if options.before_all:
            log.step('Running before_all...')
            env = options.environment.as_dictionary(prev_environment=os.environ)
+            env.setdefault('MACOSX_DEPLOYMENT_TARGET', '10.9')
            before_all_prepared = prepare_command(options.before_all, project='.', package=options.package_dir)
            call([before_all_prepared], shell=True, env=env)

-        python_configurations = get_python_configurations(options.build_selector)
+        python_configurations = get_python_configurations(options.build_selector, options.architectures)

        for config in python_configurations:
            log.build_start(config.identifier)

+            config_is_arm64 = config.identifier.endswith('arm64')
+            config_is_universal2 = config.identifier.endswith('universal2')
+
            dependency_constraint_flags: Sequence[PathOrStr] = []
            if options.dependency_constraints:
                dependency_constraint_flags = [
@@ -226,7 +328,7 @@ def build(options: BuildOptions) -> None:
            call([
                'pip', 'wheel',
                options.package_dir.resolve(),
-                '-w', built_wheel_dir,
+                '--wheel-dir', built_wheel_dir,
                '--no-deps',
                *get_build_verbosity_extra_flags(options.build_verbosity)
            ], env=env)
@@ -242,60 +344,130 @@ def build(options: BuildOptions) -> None:

            if options.repair_command:
                log.step('Repairing wheel...')
-                repair_command_prepared = prepare_command(options.repair_command, wheel=built_wheel, dest_dir=repaired_wheel_dir)
+
+                if config_is_universal2:
+                    delocate_archs = 'x86_64,arm64'
+                elif config_is_arm64:
+                    delocate_archs = 'arm64'
+                else:
+                    delocate_archs = 'x86_64'
+
+                repair_command_prepared = prepare_command(
+                    options.repair_command,
+                    wheel=built_wheel,
+                    dest_dir=repaired_wheel_dir,
+                    delocate_archs=delocate_archs,
+                )
                call(repair_command_prepared, env=env, shell=True)
            else:
                shutil.move(str(built_wheel), repaired_wheel_dir)

            repaired_wheel = next(repaired_wheel_dir.glob('*.whl'))

+            log.step_end()
+
            if options.test_command and options.test_selector(config.identifier):
-                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)
-                venv_dir = Path(tempfile.mkdtemp())
+                machine_arch = platform.machine()
+                testing_archs: List[Literal['x86_64', 'arm64']] = []

-                # Use --no-download to ensure determinism by using seed libraries
-                # built into virtualenv
-                call(['python', '-m', 'virtualenv', '--no-download', venv_dir], env=env)
+                if config_is_arm64:
+                    testing_archs = ['arm64']
+                elif config_is_universal2:
+                    testing_archs = ['x86_64', 'arm64']
+                else:
+                    testing_archs = ['x86_64']

-                virtualenv_env = env.copy()
-                virtualenv_env['PATH'] = os.pathsep.join([
-                    str(venv_dir / 'bin'),
-                    virtualenv_env['PATH'],
-                ])
+                for testing_arch in testing_archs:
+                    if config_is_universal2:
+                        arch_specific_identifier = f'{config.identifier}:{testing_arch}'
+                        if not options.test_selector(arch_specific_identifier):
+                            continue

-                # check that we are using the Python from the virtual environment
-                call(['which', 'python'], env=virtualenv_env)
+                    if machine_arch == 'x86_64' and testing_arch == 'arm64':
+                        if config_is_arm64:
+                            log.warning(unwrap('''
+                                While arm64 wheels can be built on x86_64, they cannot be tested. The
+                                ability to test the arm64 wheels will be added in a future release of
+                                cibuildwheel, once Apple Silicon CI runners are widely available. To
+                                silence this warning, set `CIBW_TEST_SKIP: *-macosx_arm64`.
+                            '''))
+                        elif config_is_universal2:
+                            log.warning(unwrap('''
+                                While universal2 wheels can be built on x86_64, the arm64 part of them
+                                cannot currently be tested. The ability to test the arm64 part of a
+                                universal2 wheel will be added in a future release of cibuildwheel, once
+                                Apple Silicon CI runners are widely available. To silence this warning,
+                                set `CIBW_TEST_SKIP: *-macosx_universal2:arm64`.
+                            '''))
+                        else:
+                            raise RuntimeError('unreachable')

-                if options.before_test:
-                    before_test_prepared = prepare_command(options.before_test, project='.', package=options.package_dir)
-                    call(before_test_prepared, env=virtualenv_env, shell=True)
+                        # skip this test
+                        continue

-                # install the wheel
-                call(['pip', 'install', str(repaired_wheel) + options.test_extras], env=virtualenv_env)
+                    log.step('Testing wheel...' if testing_arch == machine_arch else f'Testing wheel on {testing_arch}...')

-                # test the wheel
-                if options.test_requires:
-                    call(['pip', 'install'] + options.test_requires, env=virtualenv_env)
+                    # 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)
+                    venv_dir = Path(tempfile.mkdtemp())

-                # run the tests from $HOME, 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(
-                    options.test_command,
-                    project=Path('.').resolve(),
-                    package=options.package_dir.resolve()
-                )
-                call(test_command_prepared, cwd=os.environ['HOME'], env=virtualenv_env, shell=True)
+                    arch_prefix = []
+                    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']
+                        else:
+                            raise RuntimeError("don't know how to emulate {testing_arch} on {machine_arch}")

-                # clean up
-                shutil.rmtree(venv_dir)
+                    # define a custom 'call' function that adds the arch prefix each time
+                    def call_with_arch(args: Sequence[PathOrStr], **kwargs: Any) -> None:
+                        if isinstance(args, str):
+                            args = ' '.join(arch_prefix) + ' ' + args
+                        else:
+                            args = [*arch_prefix, *args]
+                        call(args, **kwargs)
+
+                    # 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)
+
+                    virtualenv_env = env.copy()
+                    virtualenv_env['PATH'] = os.pathsep.join([
+                        str(venv_dir / 'bin'),
+                        virtualenv_env['PATH'],
+                    ])
+
+                    # check that we are using the Python from the virtual environment
+                    call_with_arch(['which', 'python'], env=virtualenv_env)
+
+                    if options.before_test:
+                        before_test_prepared = prepare_command(options.before_test, project='.', package=options.package_dir)
+                        call_with_arch(before_test_prepared, env=virtualenv_env, shell=True)
+
+                    # install the wheel
+                    call_with_arch(['pip', 'install', f"{repaired_wheel}{options.test_extras}"], env=virtualenv_env)
+
+                    # test the wheel
+                    if options.test_requires:
+                        call_with_arch(['pip', 'install'] + options.test_requires, env=virtualenv_env)
+
+                    # run the tests from $HOME, 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(
+                        options.test_command,
+                        project=Path('.').resolve(),
+                        package=options.package_dir.resolve()
+                    )
+                    call_with_arch(test_command_prepared, cwd=os.environ['HOME'], env=virtualenv_env, shell=True)
+
+                    # clean up
+                    shutil.rmtree(venv_dir)

            # we're all done here; move it to output (overwrite existing)
            shutil.move(str(repaired_wheel), options.output_dir)
            log.build_end()
    except subprocess.CalledProcessError as error:
-        log.error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
+        log.step_end_with_error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
        sys.exit(1)
@@ -0,0 +1,79 @@
+import ast
+import sys
+from configparser import ConfigParser
+from pathlib import Path
+from typing import Any, Optional
+
+import toml
+
+if sys.version_info < (3, 8):
+    Constant = ast.Str
+
+    def get_constant(x: ast.Str) -> str:
+        return x.s
+
+
+else:
+    Constant = ast.Constant
+
+    def get_constant(x: ast.Constant) -> Any:
+        return x.value
+
+
+class Analyzer(ast.NodeVisitor):
+    def __init__(self) -> None:
+        self.requires_python: Optional[str] = None
+
+    def visit(self, content: ast.AST) -> None:
+        for node in ast.walk(content):
+            for child in ast.iter_child_nodes(node):
+                child.parent = node  # type: ignore
+        super().visit(content)
+
+    def visit_keyword(self, node: ast.keyword) -> None:
+        self.generic_visit(node)
+        if node.arg == "python_requires":
+            # Must not be nested in an if or other structure
+            # This will be Module -> Expr -> Call -> keyword
+            if (
+                not hasattr(node.parent.parent.parent, "parent")  # type: ignore
+                and isinstance(node.value, Constant)
+            ):
+                self.requires_python = get_constant(node.value)
+
+
+def setup_py_python_requires(content: str) -> Optional[str]:
+    try:
+        tree = ast.parse(content)
+        analyzer = Analyzer()
+        analyzer.visit(tree)
+        return analyzer.requires_python or None
+    except Exception:
+        return None
+
+
+def get_requires_python_str(package_dir: Path) -> Optional[str]:
+    "Return the python requires string from the most canonical source available, or None"
+
+    # Read in from pyproject.toml:project.requires-python
+    try:
+        info = toml.load(package_dir / 'pyproject.toml')
+        return str(info['project']['requires-python'])
+    except (FileNotFoundError, KeyError, IndexError, TypeError):
+        pass
+
+    # Read in from setup.cfg:options.python_requires
+    try:
+        config = ConfigParser()
+        config.read(package_dir / 'setup.cfg')
+        return str(config['options']['python_requires'])
+    except (FileNotFoundError, KeyError, IndexError, TypeError):
+        pass
+
+    try:
+        with open(package_dir / 'setup.py') as f:
+            return setup_py_python_requires(f.read())
+    except FileNotFoundError:
+        pass
+
+    return None
@@ -40,8 +40,10 @@ python_configurations = [
  { identifier = "cp35-macosx_x86_64", version = "3.5", url = "https://www.python.org/ftp/python/3.5.4/python-3.5.4-macosx10.6.pkg" },
  { identifier = "cp36-macosx_x86_64", version = "3.6", url = "https://www.python.org/ftp/python/3.6.8/python-3.6.8-macosx10.9.pkg" },
  { identifier = "cp37-macosx_x86_64", version = "3.7", url = "https://www.python.org/ftp/python/3.7.9/python-3.7.9-macosx10.9.pkg" },
-  { identifier = "cp38-macosx_x86_64", version = "3.8", url = "https://www.python.org/ftp/python/3.8.7/python-3.8.7-macosx10.9.pkg" },
-  { identifier = "cp39-macosx_x86_64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.1/python-3.9.1-macosx10.9.pkg" },
+  { identifier = "cp38-macosx_x86_64", version = "3.8", url = "https://www.python.org/ftp/python/3.8.9/python-3.8.9-macosx10.9.pkg" },
+  { identifier = "cp39-macosx_x86_64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
+  { identifier = "cp39-macosx_arm64", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
+  { identifier = "cp39-macosx_universal2", version = "3.9", url = "https://www.python.org/ftp/python/3.9.4/python-3.9.4-macos11.pkg" },
  { identifier = "pp27-macosx_x86_64", version = "2.7", url = "https://downloads.python.org/pypy/pypy2.7-v7.3.3-osx64.tar.bz2" },
  { identifier = "pp36-macosx_x86_64", version = "3.6", url = "https://downloads.python.org/pypy/pypy3.6-v7.3.3-osx64.tar.bz2" },
  { identifier = "pp37-macosx_x86_64", version = "3.7", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.3-osx64.tar.bz2" },
@@ -57,10 +59,10 @@ python_configurations = [
  { identifier = "cp36-win_amd64", version = "3.6.8", arch = "64" },
  { identifier = "cp37-win32", version = "3.7.9", arch = "32" },
  { identifier = "cp37-win_amd64", version = "3.7.9", arch = "64" },
-  { identifier = "cp38-win32", version = "3.8.7", arch = "32" },
-  { identifier = "cp38-win_amd64", version = "3.8.7", arch = "64" },
-  { identifier = "cp39-win32", version = "3.9.1", arch = "32" },
-  { identifier = "cp39-win_amd64", version = "3.9.1", arch = "64" },
+  { identifier = "cp38-win32", version = "3.8.9", arch = "32" },
+  { identifier = "cp38-win_amd64", version = "3.8.9", arch = "64" },
+  { identifier = "cp39-win32", version = "3.9.4", arch = "32" },
+  { identifier = "cp39-win_amd64", version = "3.9.4", arch = "64" },
  { identifier = "pp27-win32", version = "2.7", arch = "32", url = "https://downloads.python.org/pypy/pypy2.7-v7.3.3-win32.zip" },
  { identifier = "pp36-win32", version = "3.6", arch = "32", url = "https://downloads.python.org/pypy/pypy3.6-v7.3.3-win32.zip" },
  { identifier = "pp37-win32", version = "3.7", arch = "32", url = "https://downloads.python.org/pypy/pypy3.7-v7.3.3-win32.zip" },
@@ -29,7 +29,7 @@ pathlib2==2.3.5
    #   virtualenv
 scandir==1.10.0
    # via pathlib2
-singledispatch==3.4.0.3
+singledispatch==3.6.1
    # via importlib-resources
 six==1.15.0
    # via
@@ -37,7 +37,7 @@ six==1.15.0
    #   virtualenv
 typing==3.7.4.3
    # via importlib-resources
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
@@ -49,7 +49,7 @@ zipp==1.2.0
    #   importlib-resources

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==20.3.4
    # via -r cibuildwheel/resources/constraints.in
 setuptools==44.1.1
    # via -r cibuildwheel/resources/constraints.in
@@ -18,7 +18,7 @@ importlib-resources==3.2.1
    # via virtualenv
 six==1.15.0
    # via virtualenv
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
@@ -30,7 +30,7 @@ zipp==1.2.0
    #   importlib-resources

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==20.3.4
    # via -r cibuildwheel/resources/constraints.in
 setuptools==50.3.2
    # via -r cibuildwheel/resources/constraints.in
@@ -12,27 +12,27 @@ distlib==0.3.1
    # via virtualenv
 filelock==3.0.12
    # via virtualenv
-importlib-metadata==3.4.0
+importlib-metadata==3.10.0
    # via virtualenv
-importlib-resources==5.0.0
+importlib-resources==5.1.2
    # via virtualenv
 six==1.15.0
    # via virtualenv
 typing-extensions==3.7.4.3
    # via importlib-metadata
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
    #   -r cibuildwheel/resources/constraints.in
    #   delocate
-zipp==3.4.0
+zipp==3.4.1
    # via
    #   importlib-metadata
    #   importlib-resources

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==21.0.1
    # via -r cibuildwheel/resources/constraints.in
-setuptools==51.3.3
+setuptools==54.2.0
    # via -r cibuildwheel/resources/constraints.in
@@ -12,23 +12,23 @@ distlib==0.3.1
    # via virtualenv
 filelock==3.0.12
    # via virtualenv
-importlib-metadata==3.4.0
+importlib-metadata==3.10.0
    # via virtualenv
 six==1.15.0
    # via virtualenv
 typing-extensions==3.7.4.3
    # via importlib-metadata
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
    #   -r cibuildwheel/resources/constraints.in
    #   delocate
-zipp==3.4.0
+zipp==3.4.1
    # via importlib-metadata

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==21.0.1
    # via -r cibuildwheel/resources/constraints.in
-setuptools==51.3.3
+setuptools==54.2.0
    # via -r cibuildwheel/resources/constraints.in
@@ -14,7 +14,7 @@ filelock==3.0.12
    # via virtualenv
 six==1.15.0
    # via virtualenv
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
@@ -22,7 +22,7 @@ wheel==0.36.2
    #   delocate

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==21.0.1
    # via -r cibuildwheel/resources/constraints.in
-setuptools==51.3.3
+setuptools==54.2.0
    # via -r cibuildwheel/resources/constraints.in
@@ -14,7 +14,7 @@ filelock==3.0.12
    # via virtualenv
 six==1.15.0
    # via virtualenv
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
@@ -22,7 +22,7 @@ wheel==0.36.2
    #   delocate

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==21.0.1
    # via -r cibuildwheel/resources/constraints.in
-setuptools==51.3.3
+setuptools==54.2.0
    # via -r cibuildwheel/resources/constraints.in
@@ -14,7 +14,7 @@ filelock==3.0.12
    # via virtualenv
 six==1.15.0
    # via virtualenv
-virtualenv==20.3.1
+virtualenv==20.4.3
    # via -r cibuildwheel/resources/constraints.in
 wheel==0.36.2
    # via
@@ -22,7 +22,7 @@ wheel==0.36.2
    #   delocate

 # The following packages are considered to be unsafe in a requirements file:
-pip==20.3.3
+pip==21.0.1
    # via -r cibuildwheel/resources/constraints.in
-setuptools==51.3.3
+setuptools==54.2.0
    # via -r cibuildwheel/resources/constraints.in
@@ -1,22 +1,27 @@
 [x86_64]
-manylinux1 = quay.io/pypa/manylinux1_x86_64:2021-01-11-28ab838
-manylinux2010 = quay.io/pypa/manylinux2010_x86_64:2021-01-12-ff3830d
-manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2021-01-12-c8250d8
+manylinux1 = quay.io/pypa/manylinux1_x86_64:2021-04-05-14df3a6
+manylinux2010 = quay.io/pypa/manylinux2010_x86_64:2021-02-06-3d322a5
+manylinux2014 = quay.io/pypa/manylinux2014_x86_64:2021-04-05-b4fd19d
+manylinux_2_24 = quay.io/pypa/manylinux_2_24_x86_64:2021-04-05-b4fd19d

 [i686]
-manylinux1 = quay.io/pypa/manylinux1_i686:2021-01-11-28ab838
-manylinux2010 = quay.io/pypa/manylinux2010_i686:2021-01-12-ff3830d
-manylinux2014 = quay.io/pypa/manylinux2014_i686:2021-01-12-c8250d8
+manylinux1 = quay.io/pypa/manylinux1_i686:2021-04-05-14df3a6
+manylinux2010 = quay.io/pypa/manylinux2010_i686:2021-02-06-3d322a5
+manylinux2014 = quay.io/pypa/manylinux2014_i686:2021-04-05-b4fd19d
+manylinux_2_24 = quay.io/pypa/manylinux_2_24_i686:2021-04-05-b4fd19d

 [pypy_x86_64]
 manylinux2010 = pypywheels/manylinux2010-pypy_x86_64:2020-12-11-f1e0e80

 [aarch64]
-manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2021-01-12-c8250d8
+manylinux2014 = quay.io/pypa/manylinux2014_aarch64:2021-04-05-b4fd19d
+manylinux_2_24 = quay.io/pypa/manylinux_2_24_aarch64:2021-04-05-b4fd19d

 [ppc64le]
-manylinux2014 = quay.io/pypa/manylinux2014_ppc64le:2021-01-12-c8250d8
+manylinux2014 = quay.io/pypa/manylinux2014_ppc64le:2021-04-05-b4fd19d
+manylinux_2_24 = quay.io/pypa/manylinux_2_24_ppc64le:2021-04-05-b4fd19d

 [s390x]
-manylinux2014 = quay.io/pypa/manylinux2014_s390x:2021-01-12-c8250d8
+manylinux2014 = quay.io/pypa/manylinux2014_s390x:2021-04-05-b4fd19d
+manylinux_2_24 = quay.io/pypa/manylinux_2_24_s390x:2021-04-05-b4fd19d

@@ -1,30 +1,29 @@
+import contextlib
 import fnmatch
 import itertools
 import os
+import re
 import ssl
-import sys
 import textwrap
+import time
 import urllib.request
 from enum import Enum
 from pathlib import Path
 from time import sleep
-from typing import Dict, List, NamedTuple, Optional, Set
+from typing import Dict, Iterator, List, NamedTuple, Optional, Set

 import bracex
 import certifi
 import toml
+from packaging.specifiers import SpecifierSet
+from packaging.version import Version

 from .architecture import Architecture
 from .environment import ParsedEnvironment
 from .typing import PathOrStr, PlatformName

-if sys.version_info < (3, 9):
-    from importlib_resources import files
-else:
-    from importlib.resources import files
+resources_dir = Path(__file__).parent / 'resources'

-
-resources_dir = files('cibuildwheel') / 'resources'
 get_pip_script = resources_dir / 'get-pip.py'
 install_certifi_script = resources_dir / "install_certifi.py"

@@ -59,13 +58,25 @@ class IdentifierSelector:
    """
    This class holds a set of build/skip patterns. You call an instance with a
    build identifier, and it returns True if that identifier should be
-    included.
+    included. Only call this on valid identifiers, ones that have at least 2
+    numeric digits before the first dash.
    """
-    def __init__(self, *, build_config: str, skip_config: str):
+
+    def __init__(self, *, build_config: str, skip_config: str, requires_python: Optional[SpecifierSet] = None):
        self.build_patterns = build_config.split()
        self.skip_patterns = skip_config.split()
+        self.requires_python = requires_python

    def __call__(self, build_id: str) -> bool:
+        # Filter build selectors by python_requires if set
+        if self.requires_python is not None:
+            py_ver_str = build_id.split('-')[0]
+            major = int(py_ver_str[2])
+            minor = int(py_ver_str[3:])
+            version = Version(f"{major}.{minor}.99")
+            if not self.requires_python.contains(version):
+                return False
+
        build_patterns = itertools.chain.from_iterable(bracex.expand(p) for p in self.build_patterns)
        skip_patterns = itertools.chain.from_iterable(bracex.expand(p) for p in self.skip_patterns)

@@ -84,6 +95,8 @@ class BuildSelector(IdentifierSelector):
    pass


+# Note that requires-python is not needed for TestSelector, as you can't test
+# what you can't build.
 class TestSelector(IdentifierSelector):
    def __init__(self, *, skip_config: str):
        super().__init__(build_config="*", skip_config=skip_config)
@@ -196,9 +209,7 @@ class NonPlatformWheelError(Exception):


 def strtobool(val: str) -> bool:
-    if val.lower() in ('y', 'yes', 't', 'true', 'on', '1'):
-        return True
-    return False
+    return val.lower() in {'y', 'yes', 't', 'true', 'on', '1'}


 class CIProvider(Enum):
@@ -228,3 +239,35 @@ def detect_ci_provider() -> Optional[CIProvider]:
        return CIProvider.other
    else:
        return None
+
+
+def unwrap(text: str) -> str:
+    '''
+    Unwraps multi-line text to a single line
+    '''
+    # remove initial line indent
+    text = textwrap.dedent(text)
+    # remove leading/trailing whitespace
+    text = text.strip()
+    # remove consecutive whitespace
+    return re.sub(r'\s+', ' ', text)
+
+
+@contextlib.contextmanager
+def print_new_wheels(msg: str, output_dir: Path) -> Iterator[None]:
+    '''
+    Prints the new items in a directory upon exiting. The message to display
+    can include {n} for number of wheels, {s} for total number of seconds,
+    and/or {m} for total number of minutes. Does not print anything if this
+    exits via exception.
+    '''
+
+    start_time = time.time()
+    existing_contents = set(output_dir.iterdir())
+    yield
+    final_contents = set(output_dir.iterdir())
+    new_contents = final_contents - existing_contents
+    n = len(new_contents)
+    s = time.time() - start_time
+    m = s / 60
+    print(msg.format(n=n, s=s, m=m), *sorted(f"  {f.name}" for f in new_contents), sep="\n")
@@ -25,7 +25,6 @@ from .util import (
 )

 IS_RUNNING_ON_AZURE = Path('C:\\hostedtoolcache').exists()
-IS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'


 def call(args: Sequence[PathOrStr], env: Optional[Dict[str, str]] = None,
@@ -33,19 +32,24 @@ def call(args: Sequence[PathOrStr], env: Optional[Dict[str, str]] = None,
    print('+ ' + ' '.join(str(a) for a in args))
    # we use shell=True here, even though we don't need a shell due to a bug
    # https://bugs.python.org/issue8557
-    subprocess.check_call([str(a) for a in args], env=env, cwd=cwd, shell=True)
+    subprocess.run([str(a) for a in args], env=env, cwd=cwd, shell=True, check=True)


 def shell(command: str, env: Optional[Dict[str, str]] = None, cwd: Optional[str] = None) -> None:
    print(f'+ {command}')
-    subprocess.check_call(command, env=env, cwd=cwd, shell=True)
+    subprocess.run(command, env=env, cwd=cwd, shell=True, check=True)


 def get_nuget_args(version: str, arch: str) -> List[str]:
    python_name = 'python' if version[0] == '3' else 'python2'
    if arch == '32':
-        python_name = python_name + 'x86'
-    return [python_name, '-Version', version, '-OutputDirectory', 'C:\\cibw\\python']
+        python_name += 'x86'
+    return [
+        python_name,
+        '-Version', version,
+        '-FallbackSource', 'https://api.nuget.org/v3/index.json',
+        '-OutputDirectory', 'C:\\cibw\\python',
+    ]


 class PythonConfiguration(NamedTuple):
@@ -69,10 +73,9 @@ def get_python_configurations(
        '64': Architecture.AMD64,
    }

+    # Only supported with custom compiler, since MS removed the 2008 compiler download
    custom_compiler = os.environ.get('DISTUTILS_USE_SDK') and os.environ.get('MSSdk')
-    if IS_RUNNING_ON_TRAVIS and not custom_compiler:
-        # cannot install VCForPython27.msi which is needed for compiling C software
-        # try with (and similar): msiexec /i VCForPython27.msi ALLUSERS=1 ACCEPT=YES /passive
+    if not custom_compiler:
        python_configurations = [c for c in python_configurations if not c.version.startswith('2.7')]

    # skip builds as required
@@ -143,6 +146,8 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
        str(installation_path / 'Scripts'),
        env['PATH']
    ])
+    env['PIP_DISABLE_PIP_VERSION_CHECK'] = '1'
+
    # update env with results from CIBW_ENVIRONMENT
    env = environment.as_dictionary(prev_environment=env)

@@ -150,7 +155,7 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
    call(['where', 'python'], env=env)
    call(['python', '--version'], env=env)
    call(['python', '-c', '"import struct; print(struct.calcsize(\'P\') * 8)"'], env=env)
-    where_python = subprocess.check_output(['where', 'python'], env=env, universal_newlines=True).splitlines()[0].strip()
+    where_python = subprocess.run(['where', 'python'], env=env, universal_newlines=True, check=True, stdout=subprocess.PIPE).stdout.splitlines()[0].strip()
    if where_python != str(installation_path / '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)
@@ -159,7 +164,7 @@ def setup_python(python_configuration: PythonConfiguration, dependency_constrain
    if not (installation_path / 'Scripts' / 'pip.exe').exists():
        call(['python', get_pip_script, *dependency_constraint_flags], env=env, cwd="C:\\cibw")
    assert (installation_path / 'Scripts' / 'pip.exe').exists()
-    where_pip = subprocess.check_output(['where', 'pip'], env=env, universal_newlines=True).splitlines()[0].strip()
+    where_pip = subprocess.run(['where', 'pip'], env=env, universal_newlines=True, check=True, stdout=subprocess.PIPE).stdout.splitlines()[0].strip()
    if where_pip.strip() != str(installation_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)
@@ -293,13 +298,13 @@ def build(options: BuildOptions) -> None:
                ])

                # check that we are using the Python from the virtual environment
-                call(['which', 'python'], env=virtualenv_env)
+                call(['where', 'python'], env=virtualenv_env)

                if options.before_test:
                    before_test_prepared = prepare_command(
                        options.before_test,
                        project='.',
-                        package=options.package_dir
+                        package=options.package_dir,
                    )
                    shell(before_test_prepared, env=virtualenv_env)

@@ -316,7 +321,7 @@ def build(options: BuildOptions) -> None:
                test_command_prepared = prepare_command(
                    options.test_command,
                    project=Path('.').resolve(),
-                    package=options.package_dir.resolve()
+                    package=options.package_dir.resolve(),
                )
                shell(test_command_prepared, cwd='c:\\', env=virtualenv_env)

@@ -327,5 +332,5 @@ def build(options: BuildOptions) -> None:
            shutil.move(str(repaired_wheel), options.output_dir)
            log.build_end()
    except subprocess.CalledProcessError as error:
-        log.error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
+        log.step_end_with_error(f'Command {error.cmd} failed with code {error.returncode}. {error.stdout}')
        sys.exit(1)
@@ -2,9 +2,9 @@
 title: Contributing
 ---

-Wheel-building can be pretty complex. I expect users to find many edge-cases - please help the rest of the community out by documenting these, adding features to support them, and reporting bugs.
+Wheel-building can be pretty complex. We expect users to find edge-cases - please help the rest of the community out by documenting these, adding features to support them, and reporting bugs.

-I plan to be pretty liberal in accepting pull requests, as long as they align with the design goals below.
+If you have an idea for a modification or feature, it's probably best to raise an issue first and discuss it with the maintainer team. Once we have rough consensus on a design, begin work in a PR.

 `cibuildwheel` is indie open source. We're not paid to work on this.

@@ -27,12 +27,12 @@ cibuildwheel doesn't really do anything itself - it's always deferring to other

 We're not responsible for errors in those tools, for fixing errors/crashes there. But cibuildwheel's job is providing users with an 'integrated' user experience across those tools. We provide an abstraction. The user says 'build me some wheels', not 'open the docker container, build a wheel with pip, fix up the symbols with auditwheel' etc.  However, errors have a habit of breaking abstractions. And this is where users get confused, because the mechanism of cibuildwheel is laid bare, and they must understand a little bit how it works to debug.

-So, if we can, I'd like to improve the experience on errors as well. In [this](https://github.com/joerick/cibuildwheel/issues/139) case, it takes a bit of knowledge to understand that the linux builds are happening in a totally different OS via docker, that the linked symbols won't match, that auditwheel will fail because of this. A problem with how the tools fit together, instead of the tools themselves.
+So, if we can, I'd like to improve the experience on errors as well. In [this](https://github.com/joerick/cibuildwheel/issues/139) case, it takes a bit of knowledge to understand that the Linux builds are happening in a different OS via Docker, that the linked symbols won't match, that auditwheel will fail because of this. A problem with how the tools fit together, instead of the tools themselves.

 Maintainer notes
 ----------------

-## Local testing
+### Local testing

 You should run:

@@ -44,10 +44,9 @@ pip install -e .[dev]

 To prepare a development environment.

-## Testing minimal configs
+### Testing sample configs

-
-cibuildwheel's _minimal_ example configs can be tested on a simple project on cibuildwheel's existing CI. These should be run whenever the minimal configs change.
+cibuildwheel's  example configs can be tested on a simple project on cibuildwheel's existing CI. These should be run whenever the minimal configs change.

 To test minimal configs, make sure you have a clean git repo, then run the script:

@@ -57,9 +56,15 @@ bin/run_example_ci_configs.py

 The script will create an isolated 'orphan' commit containing all the minimal config CI files, and a simple C extension project, and push that to a branch on the `origin` repo. The project's CI is already set up to run on branch push, so will begin testing.

+You can test any other configs using `bin/run_example_ci_configs.py CONFIG_PATH`, e.g.
+
+```bash
+bin/run_example_ci_configs.py examples/github-with-qemu.yml
+```
+
 The script then outputs a Markdown table that can be copy/pasted into a PR to monitor and record the test.

-## Preparing environments
+### Preparing environments

 This has been moved to using docker, so you only need the following instructions if you add `--no-docker` to avoid using docker.

@@ -92,16 +97,9 @@ And, you need to install the requirements into each environment:
 for f in env*/bin/pip; do $f install pip-tools; done
 ```

+### Making a release

-## Making a release
-
-Before making a release, ensure pinned dependencies are up-to-date. Run the script:
-
-```bash
-bin/make_dependency_update_pr.py
-```
-
-If updates are needed, this will push a PR with those updates for the CI to test. Once green, merge this PR.
+Before making a release, ensure pinned dependencies are up-to-date. Autoupdates are run weekly, with a PR being raised with any changes as required, so just make sure the latest one is merged before continuing.

 Then, increment the project version number using:

@@ -111,7 +109,7 @@ 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.

-Finally, cut the release and upload to PyPI/Github.
+Finally, cut the release and upload to PyPI/GitHub.

 ```bash
 rm -rf dist
@@ -119,3 +117,5 @@ python setup.py sdist bdist_wheel
 twine upload dist/*
 git push && git push --tags
 ```
+
+Then head to https://github.com/joerick/cibuildwheel/releases and create a GitHub release from the new tag, pasting in the changelog entry.
@@ -30,9 +30,11 @@ For more details see https://en.cppreference.com/w/cpp/compiler_support, https:/

 ## Windows and Python 2.7

-Visual C++ for Python 2.7 does not support modern C++ standards (i.e., C++11 and later). When building on Appveyor, you will need to either use the "Visual Studio 2017" or "Visual Studio 2019" image, but Python 2.7 is not supported on these images - skip it by setting `CIBW_SKIP=cp27-win*`.
+In previous years, Microsoft distributed a compiler toolchain called 'Visual C++ for Python 2.7', which was a distribution of MSVC 2008 that was created to make it easier to build Python 2.7 extensions on Windows, because it was fully compatible with the toolchain that built Python 2.7.

-There is an optional workaround for this, though: the pybind11 project argues and shows that it is [possible to compile Python 2.7 extension with a newer compiler](https://pybind11.readthedocs.io/en/stable/faq.html#working-with-ancient-visual-studio-2008-builds-on-windows) and has an example project showing how to do this: https://github.com/pybind/python_example. The main catch is that a user might need to install [a newer "Microsoft Visual C++ Redistributable"](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads), since the newer C++ standard library's binaries are not included by default with the Python 2.7 installation.
+This toolchain does not support modern C++ standards (i.e., C++11 and later). And it is hard to find this toolchain these days, since Microsoft removed the download for the required Visual Studio 2008 needed to build a native extension in April, 2021. So, by default, cibuildwheel does not attempt to build Python 2.7 extensions on Windows.
+
+There is an optional workaround, though: the pybind11 project argues and shows that it is [possible to compile Python 2.7 extension with a newer compiler](https://pybind11.readthedocs.io/en/stable/faq.html#working-with-ancient-visual-studio-2008-builds-on-windows) and has an example project showing how to do this: https://github.com/pybind/python_example. The main catch is that a user might need to install [a newer "Microsoft Visual C++ Redistributable"](https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads), since the newer C++ standard library's binaries are not included by default with the Python 2.7 installation.

 Forcing `distutils` or `setuptools` to use a more recent version of MSVC that supports modern C++ can be done in the following way:

@@ -1,7 +1,8 @@
 # Fields:
 # name: required, printed name
-# gh: Github repo (eventually a url: could be added for non-github projects)
-# stars: Github repo (optional, if different from package, such as for Twisted)
+# gh: GitHub repo (eventually a url: could be added for non-github projects)
+# stars: GitHub repo (optional, if different from package, such as for Twisted)
+# pypi: The pypi name, if different from the GitHub package name
 # os: Operating system list, [windows, apple, linux] (optional)
 # ci: [appveyor, github, azurepipelines, circleci, gitlab, travisci] (optional)
 # notes: (text, optional)
@@ -29,6 +30,7 @@

 - name: Parselmouth
  gh: YannickJadoul/Parselmouth
+  pypi: praat-parselmouth
  notes: A Python interface to the Praat software package, using pybind11, C++17 and CMake, with the core Praat static library built only once and shared between wheels.
  ci: [github]
  os: [windows, apple, linux]
@@ -82,6 +84,7 @@

 - name: PyAV
  gh: PyAV-Org/PyAV
+  pypi: av
  ci: [github]
  os: [windows, apple, linux]
  notes: Pythonic bindings for FFmpeg's libraries.
@@ -109,6 +112,7 @@

 - name: etebase-py
  gh: etesync/etebase-py
+  pypi: etebase
  notes: Python bindings to a Rust library using `setuptools-rust`, and `sccache` for improved speed.
  ci: [travisci]
  os: [linux]
@@ -175,6 +179,7 @@

 - name: jq.py
  gh: mwilliamson/jq.py
+  pypi: jq
  ci: [travisci]
  os: [apple, linux]

@@ -226,6 +231,7 @@

 - name: Dependency Injector
  gh: ets-labs/python-dependency-injector
+  pypi: dependency-injector
  ci: [travisci]
  os: [windows, apple, linux]
  notes: Dependency injection framework for Python, uses Windows TravisCI
@@ -237,11 +243,13 @@

 - name: PyTables
  gh: PyTables/PyTables
+  pypi: tables
  ci: [github]
  os: [windows, apple, linux]

 - name: dd-trace-py
  gh: DataDog/dd-trace-py
+  pypi: ddtrace
  ci: [github]
  os: [windows, apple, linux]
  notes: Uses custom alternate arch emulation on GitHub
@@ -270,6 +278,7 @@
 - name: MyPy
  gh: mypyc/mypy_mypyc-wheels
  stars: python/mypy
+  pypi: mypy
  ci: [github]
  os: [apple, linux, windows]
  notes: MyPyC, the compiled component of MyPy.
@@ -277,6 +286,7 @@
 - name: Imagecodecs (fork)
  gh: czaki/imagecodecs_build
  stars: cgohlke/imagecodecs
+  pypi: imagecodecs
  ci: [azurepipelines]
  ci_config: azure-pipelines.yaml
  os: [apple, linux]
@@ -287,3 +297,30 @@
  ci: [github]
  os: [apple, linux, windows]
  notes: Extensive Cython + NumPy [pyproject.toml](https://github.com/deepcharles/ruptures/blob/master/pyproject.toml) example.
+
+- name: time-machine
+  gh: adamchainz/time-machine
+  ci: [github]
+  os: [apple, linux, windows]
+  notes: Time mocking library using only the CPython C API.
+
+- name: polaroid
+  gh: daggy1234/polaroid
+  ci: [github]
+  os: [apple, linux, windows]
+  notes: Full range of wheels for setuptools rust, with auto release and PyPI deploy.
+
+- name: python-snappy
+  gh: andrix/python-snappy
+  ci: [github]
+  os: [apple, linux, windows]
+
+- name: sourmash
+  gh: dib-lab/sourmash
+  ci: [github]
+  os: [apple, linux, windows]
+
+- name: markupsafe
+  gh: pallets/markupsafe
+  ci: [github]
+  os: [apple, linux, windows]
@@ -3,13 +3,14 @@

 p {
    margin-bottom: 12px;
+    line-height: 26px;
 }

 code {
    font-size: 85%;
    background-color: rgba(27,31,35,.05);
    border-radius: 3px;
-    padding: .2em .4em;
+    padding: .15em .4em;
    color: inherit;
    border: none;
    margin: 0 1px;
@@ -39,6 +40,14 @@ h1, h2, h3, h4, h5, h6 {
    white-space: normal;
 }

+.rst-content .admonition {
+  line-height: inherit;
+}
+
+.admonition code {
+  border: none;
+}
+
 /*
    Code block filename style

@@ -83,5 +92,65 @@ h1, h2, h3, h4, h5, h6 {
    padding-top: 0.9em;
 }

+.toctree-l3 {
+  border-left: 10px solid transparent;
+}
+
 /* import font awesome 4 for icons */
@import url(https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css);
+
+
+/* Tabs */
+
+/* Style the tab */
+.tabs {
+  margin-bottom: 1em;
+  -webkit-font-smoothing: antialiased;
+}
+
+.tabs-header {
+  background-color: white;
+  display: flex;
+  justify-content: flex-start;
+  border-bottom: 2px solid #ccc;
+}
+
+/* Style the buttons that are used to open the tab content */
+.tabs-header button {
+  background-color: transparent;
+  border: none;
+  outline: none;
+  cursor: pointer;
+  color: inherit;
+  font: inherit;
+  font-size: 0.9em;
+  font-weight: 600;
+  padding: 8px 16px;
+  border-bottom: 2px solid transparent;
+
+  /* put the border on top of the parent border */
+  margin-bottom: -2px;
+}
+
+.tabs-header button:focus-visible {
+  /* preserve an outline for accesibility purposes */
+  outline: 1px solid currentColor;
+}
+
+/* Change background color of buttons on hover */
+.tabs-header button:hover {
+  background-color: rgba(0, 0, 0, 0.02);
+}
+
+/* Create an active/current tablink class */
+.tabs-header button.active {
+  color: #4086bd;
+  border-bottom-color: currentColor;
+}
+
+/* Style the tab content */
+.tabs-content {
+  background-color: #f1f6fa;
+  padding: 1px 1em;
+  padding-top: 0.8em;
+}
@@ -1,4 +1,49 @@
-
+// add classes for code-block-filename styling
 $('.rst-content pre')
    .prev('blockquote')
    .addClass('code-block-filename');
+
+var tabConversionIterations = 0
+
+// convert tab admonition to tabs
+while (true) {
+  const firstTab = $('.rst-content .admonition.tab').first()
+  if (firstTab.length == 0) break;
+
+  const otherTabs = firstTab.nextUntil(':not(.admonition.tab)');
+  const allTabs = $($.merge($.merge([], firstTab), otherTabs));
+
+  const tabContainer = $('<div>').addClass('tabs');
+  const headerContainer = $('<div>').addClass('tabs-header');
+  const contentContainer = $('<div>').addClass('tabs-content');
+
+  tabContainer.insertBefore(firstTab);
+  tabContainer.append(headerContainer, contentContainer)
+
+  const selectTab = function (index) {
+    headerContainer.children().removeClass('active')
+    headerContainer.children().eq(index).addClass('active')
+    contentContainer.children().hide()
+    contentContainer.children().eq(index).show()
+  }
+
+  allTabs.each(function (tabI, el) {
+    const $el = $(el)
+    const titleElement = $el.children('.admonition-title')
+    const title = titleElement.text()
+    const button = $('<button>').text(title)
+    button.click(function () {
+      selectTab(tabI)
+    })
+    headerContainer.append(button)
+
+    titleElement.remove()
+    $el.removeClass('admonition')
+    contentContainer.append($el)
+  })
+
+  selectTab(0)
+
+  // this will catch infinite loops which can occur when editing the above
+  if (tabConversionIterations++ > 1000) throw 'too many iterations'
+}
@@ -12,38 +12,160 @@ If your wheel didn't compile, check the list below for some debugging tips.

 - Windows: missing C feature. The Windows C compiler doesn't support C language features invented after 1990, so you'll have to backport your C code to C90. For me, this mostly involved putting my variable declarations at the top of the function like an animal.

- MacOS: calling cibuildwheel from a python3 script and getting a `ModuleNotFoundError`? Due to a [bug](https://bugs.python.org/issue22490) in CPython, you'll need to [unset the `__PYVENV_LAUNCHER__` variable](https://github.com/joerick/cibuildwheel/issues/133#issuecomment-478288597) before activating a venv.
+- MacOS: calling cibuildwheel from a python3 script and getting a `ModuleNotFoundError`? Due to a (fixed) [bug](https://bugs.python.org/issue22490) in CPython, you'll need to [unset the `__PYVENV_LAUNCHER__` variable](https://github.com/joerick/cibuildwheel/issues/133#issuecomment-478288597) before activating a venv.

 ### Linux builds on Docker

 Linux wheels are built in the [`manylinux` docker images](https://github.com/pypa/manylinux) to provide binary compatible wheels on Linux, according to [PEP 571](https://www.python.org/dev/peps/pep-0571/). Because of this, when building with `cibuildwheel` on Linux, a few things should be taken into account:

- Programs and libraries cannot be installed on the Travis CI Ubuntu host with `apt-get`, but can be installed inside of the Docker image using `yum` or manually. The same goes for environment variables that are potentially needed to customize the wheel building. `cibuildwheel` supports this by providing the `CIBW_ENVIRONMENT` and `CIBW_BEFORE_BUILD` options to setup the build environment inside the running Docker image. See [the options docs](options.md#build-environment) for details on these options.
+- Programs and libraries are not installed on the Travis CI Ubuntu host, but rather should be installed inside of the Docker image (using `yum` for `manylinux2010` or `manylinux2014`, and `apt-get` for `manylinux_2_24`) or manually. The same goes for environment variables that are potentially needed to customize the wheel building. `cibuildwheel` supports this by providing the `CIBW_ENVIRONMENT` and `CIBW_BEFORE_BUILD` options to setup the build environment inside the running Docker image. See [the options docs](options.md#build-environment) for details on these options.

 - The project directory is mounted in the running Docker instance as `/project`, the output directory for the wheels as `/output`. In general, this is handled transparently by `cibuildwheel`. For a more finegrained level of control however, the root of the host file system is mounted as `/host`, allowing for example to access shared files, caches, etc. on the host file system.  Note that this is not available on CircleCI due to their Docker policies.

 - Alternative dockers images can be specified with the `CIBW_MANYLINUX_X86_64_IMAGE`, `CIBW_MANYLINUX_I686_IMAGE`, and `CIBW_MANYLINUX_PYPY_X86_64_IMAGE` options to allow for a custom, preconfigured build environment for the Linux builds. See [options](options.md#manylinux-image) for more details.

+### Building macOS wheels for Apple Silicon {: #apple-silicon}
+
+`cibuildwheel` supports cross-compiling `universal2` and `arm64` wheels on `x86_64` runners. With the introduction of Apple Silicon, you now have several choices for wheels for Python 3.9+:
+
+#### `x86_64`
+
+The traditional wheel for Apple, loads on Intel machines, and on
+Apple Silicon when running Python under Rosetta 2 emulation.
+
+Due to a change in naming, Pip 20.3+ (or an installer using packaging 20.5+)
+is required to install a binary wheel on macOS Big Sur.
+
+#### `arm64`
+
+The native wheel for macOS on Apple Silicon.
+
+Requires Pip 20.3+ (or packaging 20.5+) to install.
+
+#### `universal2`
+
+This wheel contains both architectures, causing it to be up to twice the
+size (data files do not get doubled, only compiled code). It requires
+Pip 20.3 (Packaging 20.6+) to load on Intel, and Pip 21.0.1 (Packaging 20.9+)
+to load on Apple Silicon.
+
+!!! note
+    The dual-architecture `universal2` has a few benefits, but a key benefit
+    to a universal wheel is that a user can bundle these wheels into an
+    application and ship a single binary.
+
+    However, if you have a large library, then you might prefer to ship
+    the two single-arch wheels instead - `x86_64` and `arm64`. In rare cases,
+    you might want to build all three, but in that case, pip will not download
+    the universal wheels, because it prefers the most specific wheel
+    available.
+
+Generally speaking, because Pip 20.3 is required for the `universal2` wheel,
+most packages should provide both `x86_64` and `universal2` wheels for now.
+Once Pip 20.3+ is common on macOS, then it should be possible to ship only the
+`universal2` wheel.
+
+**Apple Silicon wheels are not built by default**, but can be enabled by adding extra archs to the [`CIBW_ARCHS_MACOS` option](options.md#archs) - e.g. `x86_64 arm64 universal2`. Cross-compilation is provided by the Xcode toolchain.
+
+!!! important
+    When cross-compiling on Intel, it is not possible to test `arm64` and the `arm64` part of a `universal2` wheel.
+
+    `cibuildwheel` will raise a warning to notify you of this - these warnings be be silenced by skipping testing on these platforms: `CIBW_TEST_SKIP: *_arm64 *_universal2:arm64`.
+
+Hopefully, cross-compilation is a temporary situation. Once we have widely
+available Apple Silicon CI runners, we can build and test `arm64` and
+`universal2` wheels natively. That's why `universal2` wheels are not yet built
+by default, and require opt-in by setting `CIBW_ARCHS_MACOS`.
+
+!!! note
+    Your runner needs Xcode Command Line Tools 12.2 or later to build `universal2` or `arm64`.
+
+    So far, only CPython 3.9 supports `universal2` and `arm64` wheels.
+
+Here's an example GitHub Actions workflow with a job that builds for Apple Silicon:
+
+> .github/workflows/build_macos.yml
+```yml
+{% include "../examples/github-apple-silicon.yml" %}
+```
+
 ### Building non-native architectures using emulation  {: #emulation}

 cibuildwheel supports building non-native architectures on Linux, via
 emulation through the binfmt_misc kernel feature. The easiest way to use this
-is via the [docker/setup-qemu-action][setup-qemu-action] on Github Actions or
+is via the [docker/setup-qemu-action][setup-qemu-action] on GitHub Actions or
 [tonistiigi/binfmt][binfmt].

 [setup-qemu-action]: https://github.com/docker/setup-qemu-action
 [binfmt]: https://hub.docker.com/r/tonistiigi/binfmt

-Check out the following config for an example of how to set it up on Github
+Check out the following config for an example of how to set it up on GitHub
 Actions. Once QEMU is set up and registered, you just need to set the
 `CIBW_ARCHS_LINUX` environment variable (or use the `--archs` option on
 Linux), and the other architectures are emulated automatically.

 > .github/workflows/build.yml
+
 ```yaml
 {% include "../examples/github-with-qemu.yml" %}
 ```

+### Building Apple Silicon wheels on Intel {: #apple-silicon}
+
+`cibuildwheel` supports cross-compiling `universal2` and `arm64` wheels on `x86_64` runners.
+
+These wheels are not built by default, but can be enabled by setting the [`CIBW_ARCHS_MACOS` option](options.md#archs) to `x86_64 arm64 universal2`. Cross-compilation is provided by the Xcode toolchain.
+
+!!! important
+    When cross-compiling on Intel, it is not possible to test `arm64` and the `arm64` part of a `universal2` wheel.
+
+    `cibuildwheel` will raise a warning to notify you of this - these warnings be be silenced by skipping testing on these platforms: `CIBW_TEST_SKIP: *_arm64 *_universal2:arm64`.
+
+Hopefully, this is a temporary situation. Once we have widely available Apple Silicon CI runners, we can build and test `arm64` and `universal2` wheels more natively. That's why `universal2` wheels are not yet built by default, and require opt-in by setting `CIBW_ARCHS_MACOS`.
+
+!!! note
+    Your runner image needs Xcode Command Line Tools 12.2 or later to build `universal2` and `arm64`.
+
+    So far, only CPython 3.9 supports `universal2` and `arm64` wheels.
+
+Here's an example GitHub Actions workflow with a job that builds for Apple Silicon:
+
+> .github/workflows/build_macos.yml
+
+```yml
+{% include "../examples/github-apple-silicon.yml" %}
+```
+
+### Windows and Python 2.7
+
+Building 2.7 extensions on Windows is difficult, because the VS 2008 compiler that was used for the original Python compilation was discontinued in 2018, and has since been removed from Microsoft's downloads. Most people choose to not build Windows 2.7 wheels, or to override the compiler to something more modern.
+
+To override, you need to have a modern compiler toolchain activated, and set `DISTUTILS_USE_SDK=1` and `MSSdk=1`. For example, on GitHub Actions, you would add these steps:
+
+```yaml
+    - name: Prepare compiler environment for Windows
+      if: runner.os == 'Windows'
+      uses: ilammy/msvc-dev-cmd@v1
+      with:
+        arch: x64
+
+    - name: Set Windows environment variables
+      if: runner.os == 'Windows'
+      shell: bash
+      run: |
+        echo "DISTUTILS_USE_SDK=1" >> $GITHUB_ENV
+        echo "MSSdk=1" >> $GITHUB_ENV
+
+    # invoke cibuildwheel...
+```
+
+cibuildwheel will not try to build 2.7 on Windows unless it detects that the above two variables are set. Note that changing to a more modern compiler will mean your wheel picks up a runtime dependency to a different [Visual C++ Redistributable][]. You also need to be [a bit careful][] in designing your extension; some major binding tools like pybind11 do this for you.
+
+More on setting a custom Windows toolchain in our docs on modern C++ standards [here](cpp_standards.md#windows-and-python-27).
+
+[Visual C++ Redistributable]: https://support.microsoft.com/en-us/topic/the-latest-supported-visual-c-downloads-2647da03-1eea-4433-9aff-95f26a218cc0
+[a bit careful]: https://pybind11.readthedocs.io/en/stable/faq.html#working-with-ancient-visual-studio-2008-builds-on-windows
+
 ### Building packages with optional C extensions

 `cibuildwheel` defines the environment variable `CIBUILDWHEEL` to the value `1` allowing projects for which the C extension is optional to make it mandatory when building wheels.
@@ -113,7 +235,7 @@ 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: joerick/cibuildwheel@v1.8.0
+uses: joerick/cibuildwheel@v1.11.0
 ```

 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.
@@ -139,7 +261,7 @@ The second option, and the only one that supports other CI systems, is using a `

 ```bash
 # requirements-cibw.txt
-cibuildwheel==1.8.0
+cibuildwheel==1.11.0
 ```

 Then your install step would have `python -m pip install -r requirements-cibw.txt` in it. Your `dependabot.yml` file could look like this:
@@ -4,50 +4,78 @@

 ## Setting options

-cibuildwheel is configured using environment variables, that can be set using
+cibuildwheel is configured using environment variables that can be set using
 your CI config.

 For example, to configure cibuildwheel to run tests, add the following YAML to
 your CI config file:

-> .travis.yml ([docs](https://docs.travis-ci.com/user/environment-variables/))
-```yaml
-env:
-  global:
-    - CIBW_TEST_REQUIRES=pytest
-    - CIBW_TEST_COMMAND="pytest {project}/tests"
-```

-> appveyor.yml ([docs](https://www.appveyor.com/docs/build-configuration/#environment-variables))
-```yaml
-environment:
-  global:
-    CIBW_TEST_REQUIRES: pytest
-    CIBW_TEST_COMMAND: "pytest {project}\\tests"
-```
+!!! tab "GitHub Actions"

-> .circleci/config.yml ([docs](https://circleci.com/docs/2.0/configuration-reference/#environment))
-```yaml
-jobs:
-  job_name:
-    environment:
+    > .github/workflows/*.yml ([docs](https://help.github.com/en/actions/configuring-and-managing-workflows/using-environment-variables)) (can be global, in job, or in step)
+
+    ```yaml
+    env:
      CIBW_TEST_REQUIRES: pytest
      CIBW_TEST_COMMAND: "pytest {project}/tests"
-```
+    ```

-> azure-pipelines.yml ([docs](https://docs.microsoft.com/en-us/azure/devops/pipelines/process/variables))
-```yaml
-variables:
-  CIBW_TEST_REQUIRES: pytest
-  CIBW_TEST_COMMAND: "pytest {project}/tests"
-```
+!!! tab "Azure Pipelines"
+
+    > azure-pipelines.yml ([docs](https://docs.microsoft.com/en-us/azure/devops/pipelines/process/variables))
+
+    ```yaml
+    variables:
+      CIBW_TEST_REQUIRES: pytest
+      CIBW_TEST_COMMAND: "pytest {project}/tests"
+    ```
+
+!!! tab "Travis CI"
+
+    > .travis.yml ([docs](https://docs.travis-ci.com/user/environment-variables/))
+
+    ```yaml
+    env:
+      global:
+        - CIBW_TEST_REQUIRES=pytest
+        - CIBW_TEST_COMMAND="pytest {project}/tests"
+    ```
+
+!!! tab "AppVeyor"
+
+    > appveyor.yml ([docs](https://www.appveyor.com/docs/build-configuration/#environment-variables))
+
+    ```yaml
+    environment:
+      global:
+        CIBW_TEST_REQUIRES: pytest
+        CIBW_TEST_COMMAND: "pytest {project}\\tests"
+    ```
+
+!!! tab "CircleCI"
+
+    > .circleci/config.yml ([docs](https://circleci.com/docs/2.0/configuration-reference/#environment))
+
+    ```yaml
+    jobs:
+      job_name:
+        environment:
+          CIBW_TEST_REQUIRES: pytest
+          CIBW_TEST_COMMAND: "pytest {project}/tests"
+    ```
+
+!!! tab "Gitlab CI"
+
+    > .gitlab-ci.yml ([docs](https://docs.gitlab.com/ee/ci/variables/README.html#create-a-custom-variable-in-gitlab-ciyml))
+
+    ```yaml
+    linux:
+      variables:
+        CIBW_TEST_REQUIRES: pytest
+        CIBW_TEST_COMMAND: "pytest {project}/tests"
+    ```

-> .github/workflows/*.yml ([docs](https://help.github.com/en/actions/configuring-and-managing-workflows/using-environment-variables)) (can be global, in job, or in step)
-```yaml
-env:
-  CIBW_TEST_REQUIRES: pytest
-  CIBW_TEST_COMMAND: "pytest {project}/tests"
-```


 ## Build selection
@@ -62,37 +90,48 @@ Default: `auto`

 `auto` will auto-detect platform using environment variables, such as `TRAVIS_OS_NAME`/`APPVEYOR`/`CIRCLECI`.

-For `linux` you need Docker running, on macOS or Linux. For `macos`, you need a Mac machine, and note that this script is going to automatically install MacPython on your system, so don't run on your development machine. For `windows`, you need to run in Windows, and `cibuildwheel` will install required versions of Python to `C:\cibw\python` using NuGet.
+- For `linux`, you need Docker running, on macOS or Linux.
+- For `macos`, you need a Mac machine. Note that cibuildwheel is going to install MacPython on your system, so you probably don't want to run this on your development machine.
+- For `windows`, you need to run in Windows. cibuildwheel will install required versions of Python to `C:\cibw\python` using NuGet.

-This option can also be set using the command-line option `--platform`.
+This option can also be set using the [command-line option](#command-line) `--platform`.
+
+!!! tip
+    If you have Docker installed, you can locally debug your cibuildwheel Linux config, instead of pushing to CI to test every change. For example:
+
+    ```bash
+    export CIBW_BUILD='cp37-*'
+    export CIBW_TEST_COMMAND='pytest {package}/tests'
+    cibuildwheel --platform linux .
+    ```


 ### `CIBW_BUILD`, `CIBW_SKIP` {: #build-skip}

 > Choose the Python versions to build

-Space-separated list of builds to build and skip. Each build has an identifier like `cp27-manylinux_x86_64` or `cp35-macosx_x86_64` - you can list specific ones to build and `cibuildwheel` will only build those, and/or list ones to skip and `cibuildwheel` won't try to build them.
+Space-separated list of builds to build and skip. Each build has an identifier like `cp27-manylinux_x86_64` or `cp35-macosx_x86_64` - you can list specific ones to build and cibuildwheel will only build those, and/or list ones to skip and cibuildwheel won't try to build them.

 When both options are specified, both conditions are applied and only builds with a tag that matches `CIBW_BUILD` and does not match `CIBW_SKIP` will be built.

-When setting the options, you can use shell-style globbing syntax, as per [`fnmatch`](https://docs.python.org/3/library/fnmatch.html) with the addition of curly bracket syntax `{option1,option2}`, provided by [`bracex`](https://pypi.org/project/bracex/). All the build identifiers supported by cibuildwheel are shown below:
+When setting the options, you can use shell-style globbing syntax, as per [fnmatch](https://docs.python.org/3/library/fnmatch.html) with the addition of curly bracket syntax `{option1,option2}`, provided by [bracex](https://pypi.org/project/bracex/). All the build identifiers supported by cibuildwheel are shown below:

 <div class="build-id-table-marker"></div>

-|                 | macOS 64bit         | Manylinux x86 64bit    | Manylinux x86 32bit  | Windows 64bit   | Windows 32bit  | Manylinux Armv8 64bit  | Manylinux PPC64LE      | Manylinux s390x      |
-|-----------------|---------------------|------------------------|----------------------|-----------------|----------------|------------------------|------------------------|----------------------|
-| Python 2.7      | cp27-macosx_x86_64  | cp27-manylinux_x86_64  | cp27-manylinux_i686  | cp27-win_amd64  | cp27-win32     |                        |                        |                      |
-| Python 3.5      | cp35-macosx_x86_64  | cp35-manylinux_x86_64  | cp35-manylinux_i686  | cp35-win_amd64  | cp35-win32     | cp35-manylinux_aarch64 | cp35-manylinux_ppc64le | cp35-manylinux_s390x |
-| Python 3.6      | cp36-macosx_x86_64  | cp36-manylinux_x86_64  | cp36-manylinux_i686  | cp36-win_amd64  | cp36-win32     | cp36-manylinux_aarch64 | cp36-manylinux_ppc64le | cp36-manylinux_s390x |
-| Python 3.7      | cp37-macosx_x86_64  | cp37-manylinux_x86_64  | cp37-manylinux_i686  | cp37-win_amd64  | cp37-win32     | cp37-manylinux_aarch64 | cp37-manylinux_ppc64le | cp37-manylinux_s390x |
-| Python 3.8      | cp38-macosx_x86_64  | cp38-manylinux_x86_64  | cp38-manylinux_i686  | cp38-win_amd64  | cp38-win32     | cp38-manylinux_aarch64 | cp38-manylinux_ppc64le | cp38-manylinux_s390x |
-| Python 3.9      | cp39-macosx_x86_64  | cp39-manylinux_x86_64  | cp39-manylinux_i686  | cp39-win_amd64  | cp39-win32     | cp39-manylinux_aarch64 | cp39-manylinux_ppc64le | cp39-manylinux_s390x |
-| PyPy 2.7 v7.3.3 | pp27-macosx_x86_64  | pp27-manylinux_x86_64  |                      |                 | pp27-win32     |                        |                        |                      |
-| PyPy 3.6 v7.3.3 | pp36-macosx_x86_64  | pp36-manylinux_x86_64  |                      |                 | pp36-win32     |                        |                        |                      |
-| PyPy 3.7 (beta) v7.3.3 | pp37-macosx_x86_64  | pp37-manylinux_x86_64  |               |                 | pp37-win32     |                        |                        |                      |
+|              | macOS                                                               | Windows                       | Manylinux Intel                               | Manylinux Other                                                            |
+|--------------|---------------------------------------------------------------------|-------------------------------|-----------------------------------------------|----------------------------------------------------------------------------|
+| Python 2.7   | cp27-macosx_x86_64                                                  | cp27-win_amd64<br/>cp27-win32 | cp27-manylinux_x86_64<br/>cp27-manylinux_i686 |                                                                            |
+| Python 3.5   | cp35-macosx_x86_64                                                  | cp35-win_amd64<br/>cp35-win32 | cp35-manylinux_x86_64<br/>cp35-manylinux_i686 | cp35-manylinux_aarch64<br/>cp35-manylinux_ppc64le<br/>cp35-manylinux_s390x |
+| Python 3.6   | cp36-macosx_x86_64                                                  | cp36-win_amd64<br/>cp36-win32 | cp36-manylinux_x86_64<br/>cp36-manylinux_i686 | cp36-manylinux_aarch64<br/>cp36-manylinux_ppc64le<br/>cp36-manylinux_s390x |
+| Python 3.7   | cp37-macosx_x86_64                                                  | cp37-win_amd64<br/>cp37-win32 | cp37-manylinux_x86_64<br/>cp37-manylinux_i686 | cp37-manylinux_aarch64<br/>cp37-manylinux_ppc64le<br/>cp37-manylinux_s390x |
+| Python 3.8   | cp38-macosx_x86_64                                                  | cp38-win_amd64<br/>cp38-win32 | cp38-manylinux_x86_64<br/>cp38-manylinux_i686 | cp38-manylinux_aarch64<br/>cp38-manylinux_ppc64le<br/>cp38-manylinux_s390x |
+| Python 3.9   | cp39-macosx_x86_64<br/>cp39-macosx_universal2<br/>cp39-macosx_arm64 | cp39-win_amd64<br/>cp39-win32 | cp39-manylinux_x86_64<br/>cp39-manylinux_i686 | cp39-manylinux_aarch64<br/>cp39-manylinux_ppc64le<br/>cp39-manylinux_s390x |
+| PyPy2.7 v7.3 | pp27-macosx_x86_64                                                  |                    pp27-win32 | pp27-manylinux_x86_64                         |                                                                            |
+| PyPy3.6 v7.3 | pp36-macosx_x86_64                                                  |                    pp36-win32 | pp36-manylinux_x86_64                         |                                                                            |
+| PyPy3.7 v7.3 | pp37-macosx_x86_64                                                  |                    pp37-win32 | pp37-manylinux_x86_64                         |                                                                            |


-The list of supported and currently selected build identifiers can also be retrieved by passing the `--print-build-identifiers` flag to `cibuildwheel`.
+The list of supported and currently selected build identifiers can also be retrieved by passing the `--print-build-identifiers` flag to cibuildwheel.
 The format is `python_tag-platform_tag`, with tags similar to those in [PEP 425](https://www.python.org/dev/peps/pep-0425/#details).

 For CPython, the minimally supported macOS version is 10.9; for PyPy 2.7 and PyPy 3.6/3.7, respectively macOS 10.7 and 10.13 or higher is required.
@@ -155,35 +194,117 @@ CIBW_SKIP: pp*
  }
 </style>

-### `CIBW_ARCHS_LINUX` {: #archs}
-> Build non-native architectures
+### `CIBW_ARCHS` {: #archs}
+> Change the architectures built on your machine by default.

-A space-separated list of architectures to build. Use this in conjunction with
-emulation, such as that provided by [docker/setup-qemu-action][setup-qemu-action]
-or [tonistiigi/binfmt][binfmt], to build architectures other than those your
-machine natively supports.
+A space-separated list of architectures to build.

-Options: `auto` `native` `all` `x86_64` `i686` `aarch64` `ppc64le` `s390x`
+On macOS, this option can be used to cross-compile between `x86_64`,
+`universal2` and `arm64` for Apple Silicon support.

-Default: `auto`, meaning the native archs supported on the build machine. For
-example, on an `x86_64` machine, `auto` expands to `x86_64` and `i686`.
+On Linux, this option can be used to build non-native architectures under
+emulation. See [this guide](faq.md#emulation) for more information.

-`native` will only build on the exact architecture you currently are on; it will
-not add `i686` for `x86_64`.
+Options:

-`all` will expand to all known architectures; remember to use build selectors
-to limit builds for each job; this list could grow in the future.
+- Linux: `x86_64` `i686` `aarch64` `ppc64le` `s390x`
+- macOS: `x86_64` `arm64` `universal2`
+- Windows: `AMD64` `x86`
+- `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
+- `native`: the native arch of the build machine - Matches [`platform.machine()`](https://docs.python.org/3/library/platform.html#platform.machine).
+- `all` : expands to all the architectures supported on this OS. You may want
+  to use [CIBW_BUILD](#build-skip) with this option to target specific
+  architectures via build selectors.
+
+Default: `auto`
+
+| Runner | `native` | `auto` | `auto64` | `auto32` |
+|---|---|---|---|---|
+| Linux / Intel | `x86_64` | `x86_64` `i686` | `x86_64` | `i686` |
+| Windows / Intel | `AMD64` | `AMD64` `x86` | `AMD64` | `x86` |
+| macOS / Intel | `x86_64` | `x86_64` | `x86_64` |  |
+| macOS / Apple Silicon | `arm64` | `arm64` `universal2` | `arm64` `universal2`|  |
+
+If not listed above, `auto` is the same as `native`.

 [setup-qemu-action]: https://github.com/docker/setup-qemu-action
 [binfmt]: https://hub.docker.com/r/tonistiigi/binfmt

+Platform-specific variants also available:<br/>
+ `CIBW_ARCHS_MACOS` | `CIBW_ARCHS_WINDOWS` | `CIBW_ARCHS_LINUX`
+
+This option can also be set using the [command-line option](#command-line) `--archs`.
+
 #### Examples

 ```yaml
-# On an intel runner with qemu installed, build Intel and ARM wheels
+# Build `universal2` and `arm64` wheels on an Intel runner.
+# Note that the `arm64` wheel and the `arm64` part of the `universal2`
+# wheel cannot be tested in this configuration.
+CIBW_ARCHS_MACOS: "x86_64 universal2 arm64"
+
+# On an Linux Intel runner with qemu installed, build Intel and ARM wheels
 CIBW_ARCHS_LINUX: "auto aarch64"
 ```

+
+###  `CIBW_PROJECT_REQUIRES_PYTHON` {: #requires-python}
+> Manually set the Python compatibility of your project
+
+By default, cibuildwheel reads your package's Python compatibility from
+`pyproject.toml` following [PEP621](https://www.python.org/dev/peps/pep-0621/)
+or from `setup.cfg`; finally it will try to inspect the AST of `setup.py` for a
+simple keyword assignment in a top level function call. If you need to override
+this behaviour for some reason, you can use this option.
+
+When setting this option, the syntax is the same as `project.requires-python`,
+using 'version specifiers' like `>=3.6`, according to
+[PEP440](https://www.python.org/dev/peps/pep-0440/#version-specifiers).
+
+Default: reads your package's Python compatibility from `pyproject.toml`
+(`project.requires-python`) or `setup.cfg` (`options.python_requires`) or
+`setup.py` `setup(python_requires="...")`. If not found, cibuildwheel assumes
+the package is compatible with all versions of Python that it can build.
+
+
+!!! note
+    Rather than using this option, it's recommended you set
+    `project.requires-python` in `pyproject.toml` instead:
+    Example `pyproject.toml`:
+
+        [project]
+        requires-python = ">=3.6"
+
+        # Aside - in pyproject.toml you should always specify minimal build
+        # system options, like this:
+
+        [build-system]
+        requires = ["setuptools>=42", "wheel"]
+        build-backend = "setuptools.build_meta"
+
+
+    Currently, setuptools has not yet added support for reading this value from
+    pyproject.toml yet, and so does not copy it to Requires-Python in the wheel
+    metadata. This mechanism is used by pip to scan through older versions of
+    your package until it finds a release compatible with the current version
+    of Python compatible when installing, so it is an important value to set if
+    you plan to drop support for a version of Python in the future.
+
+    If you don't want to list this value twice, you can also use the setuptools
+    specific location in `setup.cfg` and cibuildwheel will detect it from
+    there. Example `setup.cfg`:
+
+        [options]
+        python_requires = ">=3.6"
+
+#### Examples
+
+```yaml
+CIBW_PROJECT_REQUIRES_PYTHON: ">=3.6"
+```
+
 ## Build customization

 ### `CIBW_ENVIRONMENT` {: #environment}
@@ -219,7 +340,7 @@ CIBW_ENVIRONMENT: "BUILD_TIME=$(date) SAMPLE_TEXT=\"sample text\""
 ```

 !!! 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#building-packages-with-optional-c-extensions).

 ### `CIBW_BEFORE_ALL` {: #before-all}
 > Execute a shell command on the build system before any wheels are built.
@@ -228,7 +349,7 @@ Shell command to prepare a common part of the project (e.g. build or install lib

 This option is very useful for the Linux build, where builds take place in isolated Docker containers managed by cibuildwheel. This command will run inside the container before the wheel builds start. Note, if you're building both x86_64 and i686 wheels (the default), your build uses two different Docker images. In that case, this command will execute twice - once per build container.

-The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
+The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by cibuildwheel.

 On Windows and macOS, the version of Python available inside `CIBW_BEFORE_ALL` is whatever is available on the host machine. On Linux, a modern Python version is available on PATH.

@@ -244,6 +365,11 @@ CIBW_BEFORE_ALL: make -C third_party_lib
 CIBW_BEFORE_ALL_LINUX: yum install -y libffi-dev
 ```

+Note that manylinux2_24 builds occur inside a Debian9 docker, where
+manylinux2010 and manylinux2014 builds occur inside a CentOS one. So for
+`manylinux2_24` the `CIBW_BEFORE_ALL_LINUX` command must use `apt-get -y`
+instead.
+
 ### `CIBW_BEFORE_BUILD` {: #before-build}
 > Execute a shell command preparing each wheel's build

@@ -251,7 +377,7 @@ A shell command to run before building the wheel. This option allows you to run

 If dependencies are required to build your wheel (for example if you include a header from a Python module), instead of using this command, we recommend adding requirements to a pyproject.toml file. This is reproducible, and users who do not get your wheels (such as Alpine or ClearLinux users) will still benefit.

-The active Python binary can be accessed using `python`, and pip with `pip`; `cibuildwheel` makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
+The active Python binary can be accessed using `python`, and pip with `pip`; cibuildwheel makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by cibuildwheel.

 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

@@ -274,27 +400,26 @@ CIBW_BEFORE_BUILD: "{package}/script/prepare_for_build.sh"
 ```

 !!! note
-    If you need dependencies installed for the build, we recommend using pyproject.toml. This is an example pyproject.toml file:
+    If you need dependencies installed for the build, we recommend using
+    `pyproject.toml`. This is an example `pyproject.toml` file:

        [build-system]
        requires = [
            "setuptools>=42",
            "wheel",
            "Cython",
-            "numpy==1.11.3; python_version<='3.6'",
-            "numpy==1.14.5; python_version=='3.7'",
-            "numpy==1.17.3; python_version=='3.8'",
-            "numpy==1.19.4; python_version>='3.9'",
+            "numpy==1.13.3; python_version<'3.5'",
+            "oldest-supported-numpy; python_version>='3.5'",
        ]

        build-backend = "setuptools.build_meta"

-    This [PEP 517][]/[PEP 518][] style build allows you to completely control the
-    build environment in cibuildwheel, [PyPA-build][], and pip, doesn't force
-    downstream users to install anything they don't need, and lets you do more
-    complex pinning (Cython, for example, requires a wheel to be built with an
-    equal or earlier version of NumPy; pinning in this way is the only way to
-    ensure your module works on all available NumPy versions).
+    This [PEP 517][]/[PEP 518][] style build allows you to completely control
+    the build environment in cibuildwheel, [PyPA-build][], and pip, doesn't
+    force downstream users to install anything they don't need, and lets you do
+    more complex pinning (Cython, for example, requires a wheel to be built
+    with an equal or earlier version of NumPy; pinning in this way is the only
+    way to ensure your module works on all available NumPy versions).

    [PyPA-build]: https://pypa-build.readthedocs.io/en/latest/
    [PEP 517]: https://www.python.org/dev/peps/pep-0517/
@@ -306,46 +431,70 @@ CIBW_BEFORE_BUILD: "{package}/script/prepare_for_build.sh"
 Default:

 - on Linux: `'auditwheel repair -w {dest_dir} {wheel}'`
- on macOS: `'delocate-listdeps {wheel} && delocate-wheel --require-archs x86_64 -w {dest_dir} {wheel}'`
+- on macOS: `'delocate-listdeps {wheel} && delocate-wheel --require-archs {delocate_archs} -w {dest_dir} {wheel}'`
 - on Windows: `''`

 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.

-The following placeholders must be used inside the command and will be replaced by `cibuildwheel`:
+The following placeholders must be used inside the command and will be replaced by cibuildwheel:

 - `{wheel}` for the absolute path to the built wheel
- `{dest_dir}` for the absolute path of the directory where to create the repaired wheel.
+- `{dest_dir}` for the absolute path of the directory where to create the repaired wheel
+- `{delocate_archs}` (macOS only) comma-separated list of architectures in the wheel.

 The command is run in a shell, so you can run multiple commands like `cmd1 && cmd2`.

 Platform-specific variants also available:<br/>
 `CIBW_REPAIR_WHEEL_COMMAND_MACOS` | `CIBW_REPAIR_WHEEL_COMMAND_WINDOWS` | `CIBW_REPAIR_WHEEL_COMMAND_LINUX`

+!!! tip
+    cibuildwheel doesn't yet ship a default repair command for Windows.
+
+    **If that's an issue for you, check out [delvewheel]** - a new package that aims to do the same as auditwheel or delocate for Windows.
+
+    Because delvewheel is still relatively early-stage, cibuildwheel does not yet run it by default. However, we'd recommend giving it a try! See the examples below for usage.
+
+    [Delvewheel]: https://github.com/adang1345/delvewheel
+
 #### Examples

 ```yaml
+# use delvewheel on windows (only works on Python 3.6+)
+CIBW_BEFORE_BUILD_WINDOWS: "pip install delvewheel"
+CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "delvewheel repair -w {dest_dir} {wheel}"
+
 # don't repair macOS wheels
 CIBW_REPAIR_WHEEL_COMMAND_MACOS: ""

 # pass the `--lib-sdir .` flag to auditwheel on Linux
 CIBW_REPAIR_WHEEL_COMMAND_LINUX: "auditwheel repair --lib-sdir . -w {dest_dir} {wheel}"
+
 ```


-### `CIBW_MANYLINUX_X86_64_IMAGE`, `CIBW_MANYLINUX_I686_IMAGE`, `CIBW_MANYLINUX_PYPY_X86_64_IMAGE`, `CIBW_MANYLINUX_AARCH64_IMAGE`, `CIBW_MANYLINUX_PPC64LE_IMAGE`, `CIBW_MANYLINUX_S390X_IMAGE` {: #manylinux-image}
-> Specify alternative manylinux docker images
+### CIBW_MANYLINUX_*_IMAGE {: #manylinux-image}
+> Specify alternative manylinux Docker images

-An alternative Docker image to be used for building [`manylinux`](https://github.com/pypa/manylinux) wheels. `cibuildwheel` will then pull these instead of the default images, [`quay.io/pypa/manylinux2010_x86_64`](https://quay.io/pypa/manylinux2010_x86_64), [`quay.io/pypa/manylinux2010_i686`](https://quay.io/pypa/manylinux2010_i686), [`pypywheels/manylinux2010-pypy_x86_64`](https://hub.docker.com/r/pypywheels/manylinux2010-pypy_x86_64), [`quay.io/pypa/manylinux2014_aarch64`](https://quay.io/pypa/manylinux2014_aarch64), [`quay.io/pypa/manylinux2014_ppc64le`](https://quay.io/pypa/manylinux2014_ppc64le), and [`quay.io/pypa/manylinux2014_s390x`](https://quay.io/pypa/manylinux2010_s390x).
+The available options are:

-The value of this option can either be set to `manylinux1`, `manylinux2010` or `manylinux2014` to use a pinned version of the [official `manylinux` images](https://github.com/pypa/manylinux) and [PyPy `manylinux` images](https://github.com/pypy/manylinux). Alternatively, set these options to any other valid Docker image name. Note that for PyPy, only the official `manylinux2010` image is currently available. For architectures other
-than x86 (x86\_64 and i686) manylinux2014 must be used because this is the first version of the manylinux specification that supports additional architectures.
+- `CIBW_MANYLINUX_X86_64_IMAGE`
+- `CIBW_MANYLINUX_I686_IMAGE`
+- `CIBW_MANYLINUX_PYPY_X86_64_IMAGE`
+- `CIBW_MANYLINUX_AARCH64_IMAGE`
+- `CIBW_MANYLINUX_PPC64LE_IMAGE`
+- `CIBW_MANYLINUX_S390X_IMAGE`

-Beware to specify a valid Docker image that can be used in the same way as the official, default Docker images: all necessary Python and pip versions need to be present in `/opt/python/`, and the `auditwheel` tool needs to be present for `cibuildwheel` to work. Apart from that, the architecture and relevant shared system libraries need to be manylinux1-, manylinux2010- or manylinux2014-compatible in order to produce valid `manylinux1`/`manylinux2010`/`manylinux2014` wheels (see [pypa/manylinux on GitHub](https://github.com/pypa/manylinux), [PEP 513](https://www.python.org/dev/peps/pep-0513/), [PEP 571](https://www.python.org/dev/peps/pep-0571/) and [PEP 599](https://www.python.org/dev/peps/pep-0599/) for more details).
+Set an alternative Docker image to be used for building [manylinux](https://github.com/pypa/manylinux) wheels. cibuildwheel will then pull these instead of the default images, [`quay.io/pypa/manylinux2010_x86_64`](https://quay.io/pypa/manylinux2010_x86_64), [`quay.io/pypa/manylinux2010_i686`](https://quay.io/pypa/manylinux2010_i686), [`pypywheels/manylinux2010-pypy_x86_64`](https://hub.docker.com/r/pypywheels/manylinux2010-pypy_x86_64), [`quay.io/pypa/manylinux2014_aarch64`](https://quay.io/pypa/manylinux2014_aarch64), [`quay.io/pypa/manylinux2014_ppc64le`](https://quay.io/pypa/manylinux2014_ppc64le), and [`quay.io/pypa/manylinux2014_s390x`](https://quay.io/pypa/manylinux2010_s390x).

-Note that `auditwheel` detects the version of the `manylinux` standard in the Docker image through the `AUDITWHEEL_PLAT` environment variable, as `cibuildwheel` has no way of detecting the correct `--plat` command line argument to pass to `auditwheel` for a custom image. If a Docker image does not correctly set this `AUDITWHEEL_PLAT` environment variable, the `CIBW_ENVIRONMENT` option can be used to do so (e.g., `CIBW_ENVIRONMENT='AUDITWHEEL_PLAT="manylinux2010_$(uname -m)"'`).
+The value of this option can either be set to `manylinux1`, `manylinux2010`, `manylinux2014` or `manylinux_2_24` to use a pinned version of the [official manylinux images](https://github.com/pypa/manylinux) and [PyPy manylinux images](https://github.com/pypy/manylinux). Alternatively, set these options to any other valid Docker image name. For PyPy, only the official `manylinux2010` image is currently available. For architectures other
+than x86 (x86\_64 and i686) `manylinux2014` or `manylinux_2_24` must be used, because the first version of the manylinux specification that supports additional architectures is `manylinux2014`.

-Note that `manylinux2014` doesn't support builds with Python 2.7 - when building with `manylinux2014`, skip Python 2.7 using `CIBW_SKIP` (see example below).
+Note that `manylinux2014`/`manylinux_2_24` don't support builds with Python 2.7 - when building with `manylinux2014`/`manylinux_2_24`, skip Python 2.7 using `CIBW_SKIP` (see example below).
+
+If setting a custom Docker image, you'll need to make sure it can be used in the same way as the official, default Docker images: all necessary Python and pip versions need to be present in `/opt/python/`, and the auditwheel tool needs to be present for cibuildwheel to work. Apart from that, the architecture and relevant shared system libraries need to be compatible to the relevant standard to produce valid manylinux1/manylinux2010/manylinux2014/manylinux_2_24 wheels (see [pypa/manylinux on GitHub](https://github.com/pypa/manylinux), [PEP 513](https://www.python.org/dev/peps/pep-0513/), [PEP 571](https://www.python.org/dev/peps/pep-0571/), [PEP 599](https://www.python.org/dev/peps/pep-0599/) and [PEP 600](https://www.python.org/dev/peps/pep-0600/) for more details).
+
+Auditwheel detects the version of the manylinux standard in the Docker image through the `AUDITWHEEL_PLAT` environment variable, as cibuildwheel has no way of detecting the correct `--plat` command line argument to pass to auditwheel for a custom image. If a Docker image does not correctly set this `AUDITWHEEL_PLAT` environment variable, the `CIBW_ENVIRONMENT` option can be used to do so (e.g., `CIBW_ENVIRONMENT='AUDITWHEEL_PLAT="manylinux2010_$(uname -m)"'`).

 #### Examples

@@ -427,10 +576,17 @@ CIBW_DEPENDENCY_VERSIONS: ./constraints.txt
 ### `CIBW_TEST_COMMAND` {: #test-command}
 > Execute a shell command to test each built wheel

-Shell command to run tests after the build. The wheel will be installed automatically and available for import from the tests. To ensure the wheel is imported by your tests (instead of your source copy), tests are run from a different directory. Use the placeholders `{project}` and `{package}` when specifying paths in your project.
+Shell command to run tests after the build. The wheel will be installed
+automatically and available for import from the tests. To ensure the wheel is
+imported by your tests (instead of your source copy), **tests are not run from
+your project directory**. Use the placeholders `{project}` and `{package}` when
+specifying paths in your project. If this variable is not set, your wheel will
+not be installed after building.

- `{project}` is an absolute path to the project root - the working directory where cibuildwheel was called.
- `{package}` is the path to the package being built - the `package_dir` argument supplied to cibuildwheel on the command line.
+- `{project}` is an absolute path to the project root - the working directory
+  where cibuildwheel was called.
+- `{package}` is the path to the package being built - the `package_dir`
+  argument supplied to cibuildwheel on the command line.

 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

@@ -445,16 +601,19 @@ CIBW_TEST_COMMAND: nosetests {project}/tests

 # run the package tests using `pytest`
 CIBW_TEST_COMMAND: pytest {package}/tests
+
+# trigger an install of the package, but run nothing of note
+CIBW_TEST_COMMAND: "echo Wheel installed"
 ```


 ### `CIBW_BEFORE_TEST` {: #before-test}
 > Execute a shell command before testing each wheel

-A shell command to run in **each** test virtual environment, before your wheel is installed and tested. This is useful if you need to install a non pip package, change values of environment variables
-or perform multi step pip installation (e.g. installing `scikit-build` or `cython` before install test package)
+A shell command to run in **each** test virtual environment, before your wheel is installed and tested. This is useful if you need to install a non-pip package, invoke pip with different environment variables,
+or perform a multi-step pip installation (e.g. installing scikit-build or Cython before installing test package).

-The active Python binary can be accessed using `python`, and pip with `pip`; `cibuildwheel` makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by `cibuildwheel`.
+The active Python binary can be accessed using `python`, and pip with `pip`; cibuildwheel makes sure the right version of Python and pip will be executed. The placeholder `{package}` can be used here; it will be replaced by the path to the package being built by cibuildwheel.

 The command is run in a shell, so you can write things like `cmd1 && cmd2`.

@@ -519,13 +678,18 @@ CIBW_TEST_EXTRAS: test,qt
 ### `CIBW_TEST_SKIP` {: #test-skip}
 > Skip running tests on some builds

-This will skip testing on any identifiers that match the given skip patterns (see [`CIBW_SKIP`](#build-skip)). This can be used to mask out tests for wheels that have missing dependencies upstream that are slow or hard to build, or to mask up slow tests on emulated architectures.
+This will skip testing on any identifiers that match the given skip patterns (see [`CIBW_SKIP`](#build-skip)). This can be used to mask out tests for wheels that have missing dependencies upstream that are slow or hard to build, or to skip slow tests on emulated architectures.
+
+With macOS `universal2` wheels, you can also skip the the individual archs inside the wheel using an `:arch` suffix. For example, `cp39-macosx_universal2:x86_64` or `cp39-macosx_universal2:arm64`.

 #### Examples

 ```yaml
 # Will avoid testing on emulated architectures
 CIBW_TEST_SKIP: "*-manylinux_{aarch64,ppc64le,s390x}"
+
+# Skip trying to test arm64 builds on Intel Macs
+CIBW_TEST_SKIP: "*-macosx_arm64 *-macosx_universal2:arm64"
 ```


@@ -547,7 +711,7 @@ CIBW_BUILD_VERBOSITY: 1
 ```


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

 ```text
 usage: cibuildwheel [-h] [--platform {auto,linux,macos,windows}]
@@ -591,18 +755,15 @@ optional arguments:
 ```

 <style>
-  .toctree-l3 {
-    border-left: 10px solid transparent;
-  }
-
  .options-toc {
    display: grid;
-    grid-auto-columns: fit-content(20%) 1fr;
+    grid-template-columns: fit-content(20%) 1fr;
    grid-gap: 16px 32px;
    gap: 16px 32px;
    font-size: 90%;
    margin-bottom: 28px;
    margin-top: 28px;
+    overflow-x: auto;
  }
  .options-toc .header {
    grid-column: 1 / 3;
@@ -628,7 +789,7 @@ optional arguments:

    $('.rst-content h3')
      .filter(function (i, el) {
-        return !!$(el).text().match(/(^([A-Z0-9, _]| and )+)¶$/);
+        return !!$(el).text().match(/(^([A-Z0-9, _*]| and )+)¶$/);
      })
      .each(function (i, el) {
        var optionName = $(el).text().replace('¶', '');
@@ -4,26 +4,107 @@ title: 'Setup'

 # GitHub Actions [linux/mac/windows] {: #github-actions}

-To build Linux, Mac, and Windows wheels using Github Actions, create a `.github/workflows/build.yml` file in your repo.
+To build Linux, Mac, and Windows wheels using GitHub Actions, create a `.github/workflows/build_wheels.yml` file in your repo.

-> build.yml
-```yaml
-{% include "../examples/github-minimal.yml" %}
-```
+!!! tab "Action"
+    For GitHub Actions, `cibuildwheel` provides an action you can use. This is
+    concise and enables easier auto updating via GitHub's Dependabot; see
+    [Automatic updates](faq.md#automatic-updates).

-Commit this file, and push to Github - either to your default branch, or to a PR branch. The build should start automatically.
+    > .github/workflows/build_wheels.yml
+
+    ```yaml
+    {% include "../examples/github-minimal.yml" %}
+    ```
+
+
+    You can use `env:` with the action just like you would with `run:`; you can
+    also use `with:` to set the command line options: `package-dir: .` and
+    `output-dir: wheelhouse` (those values are the defaults).
+
+!!! tab "pipx"
+    The GitHub Actions runners have pipx installed, so you can easily build in
+    just one line. This is internally how the action works; the main benefit of
+    the action form is easy updates via GitHub's Dependabot.
+
+    > .github/workflows/build_wheels.yml
+
+    ```yaml
+    name: Build
+
+    on: [push, pull_request]
+
+    jobs:
+      build_wheels:
+        name: Build wheels on ${{ matrix.os }}
+        runs-on: ${{ matrix.os }}
+        strategy:
+          matrix:
+            os: [ubuntu-20.04, windows-2019, macos-10.15]
+
+        steps:
+          - uses: actions/checkout@v2
+
+          - name: Build wheels
+            run: pipx run cibuildwheel==1.11.0
+
+          - uses: actions/upload-artifact@v2
+            with:
+              path: ./wheelhouse/*.whl
+    ```
+
+!!! tab "Generic"
+    This is the most generic form using setup-python and pip; it looks the most
+    like the other CI examples. If you want to avoid having setup that takes
+    advantage of GitHub Actions features or pipx being preinstalled, this might
+    appeal to you.
+
+    > .github/workflows/build_wheels.yml
+
+    ```yaml
+    name: Build
+
+    on: [push, pull_request]
+
+    jobs:
+      build_wheels:
+        name: Build wheels on ${{ matrix.os }}
+        runs-on: ${{ matrix.os }}
+        strategy:
+          matrix:
+            os: [ubuntu-20.04, windows-2019, macos-10.15]
+
+        steps:
+          - uses: actions/checkout@v2
+
+          # Used to host cibuildwheel
+          - uses: actions/setup-python@v2
+
+          - name: Install cibuildwheel
+            run: python -m pip install cibuildwheel==1.11.0
+
+          - name: Build wheels
+            run: python -m cibuildwheel --output-dir wheelhouse
+
+          - uses: actions/upload-artifact@v2
+            with:
+              path: ./wheelhouse/*.whl
+    ```
+
+
+Commit this file, and push to GitHub - either to your default branch, or to a PR branch. The build should start automatically.

 For more info on this file, check out the [docs](https://help.github.com/en/actions/reference/workflow-syntax-for-github-actions).

 [`examples/github-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/github-deploy.yml) extends this minimal example with a demonstration of how to automatically upload the built wheels to PyPI.

-You can also use cibuildwheel directly as an action with `uses: joerick/cibuildwheel@v1.8.0`; this combines the download and run steps into a single action, and command line arguments are available via `with:`. This makes it easy to manage cibuildwheel updates via normal actions update mechanisms like dependabot, see [Automatic updates](faq.md#automatic-updates).

 # Azure Pipelines [linux/mac/windows] {: #azure-pipelines}

 To build Linux, Mac, and Windows wheels on Azure Pipelines, create a `azure-pipelines.yml` file in your repo.

 > azure-pipelines.yml
+
 ```yaml
 {% include "../examples/azure-pipelines-minimal.yml" %}
 ```
@@ -40,6 +121,7 @@ Wheels will be stored for you and available through the Pipelines interface. For
 To build Linux, Mac, and Windows wheels on Travis CI, create a `.travis.yml` file in your repo.

 > .travis.yml
+
 ```yaml
 {% include "../examples/travis-ci-minimal.yml" %}
 ```
@@ -52,35 +134,6 @@ Then setup a deployment method by following the [Travis CI deployment docs](http

 [`examples/travis-ci-deploy.yml`](https://github.com/joerick/cibuildwheel/blob/master/examples/travis-ci-deploy.yml) extends this minimal example with a demonstration of how to automatically upload the built wheels to PyPI.

-# CircleCI [linux/mac] {: #circleci}
-
-To build Linux and Mac wheels on CircleCI, create a `.circleci/config.yml` file in your repo,
-
-> .circleci/config.yml
-```yaml
-{% include "../examples/circleci-minimal.yml" %}
-```
-
-Commit this file, enable building of your repo on CircleCI, and push.
-
-!!! note
-    CircleCI doesn't enable free macOS containers for open source by default, but you can ask for access. See [here](https://circleci.com/docs/2.0/oss/#overview) for more information.
-
-CircleCI will store the built wheels for you - you can access them from the project console. Check out the CircleCI [docs](https://circleci.com/docs/2.0/configuration-reference/#section=configuration) for more info on this config file.
-
-# Gitlab CI [linux] {: #gitlab-ci}
-
-To build Linux wheels on Gitlab CI, create a `.gitlab-ci.yml` file in your repo,
-
-> .gitlab-ci.yml
-```yaml
-{% include "../examples/gitlab-minimal.yml" %}
-```
-
-Commit this file, and push to Gitlab. The pipeline should start automatically.
-
-Gitlab will store the built wheels for you - you can access them from the Pipelines view. Check out the Gitlab [docs](https://docs.gitlab.com/ee/ci/yaml/) for more info on this config file.
-
 # AppVeyor [linux/mac/windows] {: #appveyor}

 To build Linux, Mac, and Windows wheels on AppVeyor, create an `appveyor.yml` file in your repo.
@@ -97,6 +150,37 @@ AppVeyor will store the built wheels for you - you can access them from the proj

 For more info on this config file, check out the [docs](https://www.appveyor.com/docs/).

+# CircleCI [linux/mac] {: #circleci}
+
+To build Linux and Mac wheels on CircleCI, create a `.circleci/config.yml` file in your repo,
+
+> .circleci/config.yml
+
+```yaml
+{% include "../examples/circleci-minimal.yml" %}
+```
+
+Commit this file, enable building of your repo on CircleCI, and push.
+
+!!! note
+    CircleCI doesn't enable free macOS containers for open source by default, but you can ask for access. See [here](https://circleci.com/docs/2.0/oss/#overview) for more information.
+
+CircleCI will store the built wheels for you - you can access them from the project console. Check out the CircleCI [docs](https://circleci.com/docs/2.0/configuration-reference/#section=configuration) for more info on this config file.
+
+# Gitlab CI [linux] {: #gitlab-ci}
+
+To build Linux wheels on Gitlab CI, create a `.gitlab-ci.yml` file in your repo,
+
+> .gitlab-ci.yml
+
+```yaml
+{% include "../examples/gitlab-minimal.yml" %}
+```
+
+Commit this file, and push to Gitlab. The pipeline should start automatically.
+
+Gitlab will store the built wheels for you - you can access them from the Pipelines view. Check out the Gitlab [docs](https://docs.gitlab.com/ee/ci/yaml/) for more info on this config file.
+
 > ⚠️ Got an error? Check the [FAQ](faq.md).

 <script>
@@ -12,7 +12,7 @@ stack: python 3.7
 init:
 - cmd: set PATH=C:\Python37;C:\Python37\Scripts;%PATH%

-install: python -m pip install cibuildwheel==1.8.0
+install: python -m pip install cibuildwheel==1.11.0

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

@@ -6,7 +6,7 @@ jobs:
    - bash: |
        set -o errexit
        python3 -m pip install --upgrade pip
-        pip3 install cibuildwheel==1.8.0
+        pip3 install cibuildwheel==1.11.0
      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==1.8.0
+        python3 -m pip install cibuildwheel==1.11.0
      displayName: Install dependencies
    - bash: cibuildwheel --output-dir wheelhouse .
      displayName: Build wheels
@@ -31,12 +31,10 @@ jobs:
  pool: {vmImage: 'vs2017-win2016'}
  steps:
    - task: UsePythonVersion@0
-    - script: choco install vcpython27 -f -y
-      displayName: Install Visual C++ for Python 2.7
    - bash: |
        set -o errexit
        python -m pip install --upgrade pip
-        pip install cibuildwheel==1.8.0
+        pip install cibuildwheel==1.11.0
      displayName: Install dependencies
    - bash: cibuildwheel --output-dir wheelhouse .
      displayName: Build wheels
@@ -11,7 +11,7 @@ jobs:
      - run:
          name: Build the Linux wheels.
          command: |
-            pip3 install --user cibuildwheel==1.8.0
+            pip3 install --user cibuildwheel==1.11.0
            cibuildwheel --output-dir wheelhouse
      - store_artifacts:
          path: wheelhouse/
@@ -25,7 +25,7 @@ jobs:
      - run:
          name: Build the OS X wheels.
          command: |
-            pip3 install cibuildwheel==1.8.0
+            pip3 install cibuildwheel==1.11.0
            cibuildwheel --output-dir wheelhouse
      - store_artifacts:
          path: wheelhouse/
@@ -0,0 +1,19 @@
+name: Build
+
+on: [push, pull_request]
+
+jobs:
+  build_wheels_macos:
+    name: Build wheels on macos-10.15
+    runs-on: macos-10.15
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Build wheels
+        uses: joerick/cibuildwheel@v1.11.0
+        env:
+          CIBW_ARCHS_MACOS: x86_64 universal2
+
+      - uses: actions/upload-artifact@v2
+        with:
+          path: ./wheelhouse/*.whl
@@ -16,7 +16,7 @@ jobs:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
-        os: [ubuntu-18.04, windows-2019, macos-10.15]
+        os: [ubuntu-20.04, windows-2019, macos-10.15]

    steps:
      - uses: actions/checkout@v2
@@ -24,20 +24,10 @@ jobs:
      - uses: actions/setup-python@v2
        name: Install Python
        with:
-          python-version: '3.7'
-
-      - name: Install cibuildwheel
-        run: |
-          python -m pip install cibuildwheel==1.8.0
-
-      - name: Install Visual C++ for Python 2.7
-        if: runner.os == 'Windows'
-        run: |
-          choco install vcpython27 -f -y
+          python-version: '3.8'

      - name: Build wheels
-        run: |
-          python -m cibuildwheel --output-dir wheelhouse
+        uses: joerick/cibuildwheel@v1.11.0

      - uses: actions/upload-artifact@v2
        with:
@@ -52,7 +42,7 @@ jobs:
      - uses: actions/setup-python@v2
        name: Install Python
        with:
-          python-version: '3.7'
+          python-version: '3.8'

      - name: Build sdist
        run: python setup.py sdist
@@ -8,28 +8,16 @@ jobs:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
-        os: [ubuntu-18.04, windows-2019, macos-10.15]
+        os: [ubuntu-20.04, windows-2019, macos-10.15]

    steps:
      - uses: actions/checkout@v2

-      - uses: actions/setup-python@v2
-        name: Install Python
-        with:
-          python-version: '3.7'
-
-      - name: Install cibuildwheel
-        run: |
-          python -m pip install cibuildwheel==1.8.0
-
-      - name: Install Visual C++ for Python 2.7
-        if: runner.os == 'Windows'
-        run: |
-          choco install vcpython27 -f -y
-
      - name: Build wheels
-        run: |
-          python -m cibuildwheel --output-dir wheelhouse
+        uses: joerick/cibuildwheel@v1.11.0
+        # to supply options, put them in 'env', like:
+        # env:
+        #   CIBW_SOME_OPTION: value

      - uses: actions/upload-artifact@v2
        with:
@@ -8,7 +8,7 @@ jobs:
    runs-on: ${{ matrix.os }}
    strategy:
      matrix:
-        os: [ubuntu-18.04, windows-2019, macos-10.15]
+        os: [ubuntu-20.04, windows-2019, macos-10.15]

    steps:
      - uses: actions/checkout@v2
@@ -18,15 +18,6 @@ jobs:
        with:
          python-version: '3.7'

-      - name: Install cibuildwheel
-        run: |
-          python -m pip install cibuildwheel==1.8.0
-
-      - name: Install Visual C++ for Python 2.7
-        if: runner.os == 'Windows'
-        run: |
-          choco install vcpython27 -f -y
-
      - name: Set up QEMU
        if: runner.os == 'Linux'
        uses: docker/setup-qemu-action@v1
@@ -34,8 +25,7 @@ jobs:
          platforms: all

      - name: Build wheels
-        run: |
-          python -m cibuildwheel --output-dir wheelhouse
+        uses: joerick/cibuildwheel@v1.11.0
        env:
          # configure cibuildwheel to build native archs ('auto'), and some
          # emulated ones
@@ -12,7 +12,7 @@ linux:
    DOCKER_TLS_CERTDIR: ""
  script:
    - curl -sSL https://get.docker.com/ | sh
-    - python -m pip install cibuildwheel
+    - python -m pip install cibuildwheel==1.11.0
    - cibuildwheel --output-dir wheelhouse
  artifacts:
    paths:
@@ -14,13 +14,13 @@ jobs:
    - os: windows
      language: shell
      before_install:
-        - choco install python --version 3.8.0
+        - choco upgrade python -y --version 3.8.6
        - export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
        # make sure it's on PATH as 'python3'
        - ln -s /c/Python38/python.exe /c/Python38/python3.exe

 install:
-  - python3 -m pip install cibuildwheel==1.8.0
+  - python3 -m pip install cibuildwheel==1.11.0

 script:
  # build the wheels, put them into './wheelhouse'
@@ -20,13 +20,13 @@ jobs:
    - os: windows
      language: shell
      before_install:
-        - choco install python --version 3.8.0
+        - choco upgrade python -y --version 3.8.6
        - export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
        # make sure it's on PATH as 'python3'
        - ln -s /c/Python38/python.exe /c/Python38/python3.exe

 install:
-  - python3 -m pip install cibuildwheel==1.8.0
+  - python3 -m pip install cibuildwheel==1.11.0

 script:
  # build the wheels, put them into './wheelhouse'
@@ -14,7 +14,7 @@ python:
 before_install:
  - |
    if [[ "$TRAVIS_OS_NAME" = windows ]]; then
-        choco install python --version 3.8.0
+        choco upgrade python -y --version 3.8.6
        export PATH="/c/Python38:/c/Python38/Scripts:$PATH"
        # make sure it's on PATH as 'python3'
        ln -s /c/Python38/python.exe /c/Python38/python3.exe
@@ -55,7 +55,7 @@ jobs:
    - stage: deploy
      name: Build and deploy Linux wheels
      services: docker
-      install: python3 -m pip install cibuildwheel==1.8.0
+      install: python3 -m pip install cibuildwheel==1.11.0
      script: python3 -m cibuildwheel --output-dir wheelhouse
      after_success: |
        python3 -m pip install twine
@@ -65,7 +65,7 @@ jobs:
      name: Build and deploy macOS wheels
      os: osx
      language: shell
-      install: python3 -m pip install cibuildwheel==1.8.0
+      install: python3 -m pip install cibuildwheel==1.11.0
      script: python3 -m cibuildwheel --output-dir wheelhouse
      after_success: |
        python3 -m pip install twine
@@ -75,7 +75,7 @@ jobs:
      name: Build and deploy Windows wheels
      os: windows
      language: shell
-      install: python3 -m pip install cibuildwheel==1.8.0
+      install: python3 -m pip install cibuildwheel==1.11.0
      script: python3 -m cibuildwheel --output-dir wheelhouse
      after_success: |
        python3 -m pip install twine
@@ -25,13 +25,18 @@ nav:
  - changelog.md

 markdown_extensions:
-  - fenced_code
+  - md_in_html
  - toc:
      permalink: True
  - attr_list
  - admonition
  - pymdownx.magiclink:
      repo_url_shortener: True
+  - pymdownx.highlight:
+      # use highlightjs - it's built-in to the theme
+      use_pygments: False
+  - pymdownx.superfences

 plugins:
  - include-markdown
+  - search
@@ -5,3 +5,8 @@ requires = [
 ]

 build-backend = "setuptools.build_meta"
+
+[tool.black]
+line-length = 120
+target-version = ['py36', 'py37', 'py38']
+skip-string-normalization = true
@@ -1 +1 @@
-e .[dev]
+-e .[dev,docs]
@@ -1,97 +1,87 @@
 [metadata]
-
 name = cibuildwheel
-version = 1.8.0
+version = 1.11.0
 description = Build Python wheels on CI with minimal configuration.
 long_description = file: README.md
 long_description_content_type = text/markdown
+url = https://github.com/joerick/cibuildwheel
 author = Joe Rickerby
 author_email = joerick@mac.com
-url = https://github.com/joerick/cibuildwheel
 license = BSD
+license_file = LICENSE
 classifiers =
+    Development Status :: 5 - Production/Stable
    Intended Audience :: Developers
+    License :: OSI Approved :: BSD License
    Natural Language :: English
    Programming Language :: Python :: 3
-    Development Status :: 5 - Production/Stable
-    License :: OSI Approved :: BSD License
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
    Programming Language :: Python :: Implementation :: CPython
    Topic :: Software Development :: Build Tools
+keywords = ci,wheel,packaging,pypi,travis,appveyor,macos,linux,windows
 project_urls =
    Changelog=https://github.com/joerick/cibuildwheel#changelog
    Documentation=https://cibuildwheel.readthedocs.io/
-keywords = ci,wheel,packaging,pypi,travis,appveyor,macos,linux,windows

 [options]
 packages = find:
-zip_safe = False
-include_package_data = True
-python_requires = >=3.6
 install_requires =
    bashlex!=0.13
-    toml
-    certifi
    bracex
-    typing_extensions; python_version < '3.8'
-    importlib_resources>=1.4; python_version < '3.9'
-
-[options.package_data]
-cibuildwheel = resources/*
-
-[options.extras_require]
-dev =
-    click
-    mkdocs-include-markdown-plugin==2.1.1
-    mkdocs==1.0.4
-    mypy
-    pip-tools
-    pygithub
-    pymdown-extensions
-    pytest
-    pytest-timeout
-    pyyaml
-    requests
-    typing-extensions
-    packaging>=20.8
-    rich>=9.6
-
-[options.packages.find]
-include =
-    cibuildwheel
+    certifi
+    packaging
+    toml
+    typing_extensions;python_version < '3.8'
+python_requires = >=3.6
+include_package_data = True
+zip_safe = False

 [options.entry_points]
 console_scripts =
    cibuildwheel = cibuildwheel.__main__:main

+[options.package_data]
+cibuildwheel = resources/*
+
+[options.packages.find]
+include =
+    cibuildwheel

 [flake8]
 ignore = E501,W503,E741,E226,B950
 select = C,E,F,W,B,B9
 application-import-names = cibuildwheel
 exclude =
-  cibuildwheel/resources/,
-  dist/,
-  build/,
-  .git/,
-  env/,
-  env2/,
-  env??/,
-  .venv/,
-  site/
+    cibuildwheel/resources/,
+    dist/,
+    build/,
+    .git/,
+    env/,
+    env2/,
+    env??/,
+    .venv/,
+    site/

 [tool:pytest]
-junit_family=xunit2
+junit_family = xunit2
+testpaths =
+    test
+    unit_test

 [mypy]
-python_version = 3.6
-files = cibuildwheel,test,unit_test,bin
+python_version = 3.7
+files = cibuildwheel/*.py,test/**/*.py,unit_test/**/*.py,bin/*.py
 warn_unused_configs = True
 warn_redundant_casts = True

-[mypy-test.*]
+[mypy-test.*,mypy-unit_test.*]
 check_untyped_defs = True

-[mypy-cibuildwheel.*,unit_test.*]
+[mypy-cibuildwheel.*]
 disallow_any_generics = True
 disallow_subclassing_any = True
 disallow_untyped_calls = True
@@ -123,6 +113,9 @@ ignore_missing_imports = True
 [mypy-bracex.*]
 ignore_missing_imports = True

+[mypy-importlib_resources.*]
+ignore_missing_imports = True
+
 [tool:isort]
-profile=black
-multi_line_output=3
+profile = black
+multi_line_output = 3
@@ -1,3 +1,31 @@
 from setuptools import setup

-setup()
+extras = {
+    "docs": [
+        "mkdocs-include-markdown-plugin==2.8.0",
+        "mkdocs==1.0.4",
+        "pymdown-extensions",
+    ],
+    "test": [
+        "jinja2",
+        "pytest>=4",
+        "pytest-timeout",
+    ],
+    "dev": [
+        "click",
+        "ghapi",
+        "mypy>=0.800",
+        "packaging>=20.8",
+        "pip-tools",
+        "pygithub",
+        "pyyaml",
+        "requests",
+        "rich>=9.6",
+        "typing-extensions",
+    ],
+}
+
+extras["all"] = sum(extras.values(), [])
+extras["dev"] += extras["test"]
+
+setup(extras_require=extras)
@@ -31,7 +31,7 @@ def test(tmp_path):
        # write python version information to a temporary file, this is
        # checked in setup.py
        'CIBW_BEFORE_ALL': before_all_command,
-        'CIBW_BEFORE_ALL_LINUX': 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, 6)"',
        'CIBW_ENVIRONMENT': "TEST_VAL='123'"
    })

@@ -7,7 +7,7 @@ from . import test_projects, utils

 project_with_before_build_asserts = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(r'''
-        import sys, os
+        import os

        # assert that the Python version as written to pythonversion.txt in the CIBW_BEFORE_BUILD step
        # is the same one as is currently running.
@@ -40,11 +40,10 @@ VERSION_REGEX = r'([\w-]+)==([^\s]+)'
 def get_versions_from_constraint_file(constraint_file):
    constraint_file_text = constraint_file.read_text(encoding='utf8')

-    versions = {}
-    for package, version in re.findall(VERSION_REGEX, constraint_file_text):
-        versions[package] = version
-
-    return versions
+    return {
+        package: version
+        for package, version in re.findall(VERSION_REGEX, constraint_file_text)
+    }


@pytest.mark.parametrize('python_version', ['2.7', '3.5', '3.6', '3.8'])
@@ -52,8 +51,15 @@ def test_pinned_versions(tmp_path, python_version):
    if utils.platform == 'linux':
        pytest.skip('linux doesn\'t pin individual tool versions, it pins manylinux images instead')

-    if utils.IS_WINDOWS_RUNNING_ON_TRAVIS and python_version == '2.7':
-        pytest.skip('Windows + Travis CI requires a workaround')
+    if utils.platform == 'windows' and python_version == '2.7':
+        pytest.skip('Windows requires a workaround')
+
+    is_running_on_macos_11_or_later = (
+        utils.platform == 'macos' and utils.get_macos_version() >= (10, 16)
+    )
+
+    if is_running_on_macos_11_or_later and python_version == '3.5':
+        pytest.skip('CPython 3.5 doesn\'t work on macOS Big Sur+')

    project_dir = tmp_path / 'project'
    project_with_expected_version_checks.generate(project_dir)
@@ -84,7 +90,7 @@ def test_pinned_versions(tmp_path, python_version):
        build_environment[env_name] = constraint_versions[package]

    cibw_environment_option = ' '.join(
-        [f'{k}={v}' for k, v in build_environment.items()]
+        f'{k}={v}' for k, v in build_environment.items()
    )

    # build and test the wheels
@@ -117,7 +123,7 @@ def test_dependency_constraints_file(tmp_path, python_version):
    if utils.platform == 'linux':
        pytest.skip('linux doesn\'t pin individual tool versions, it pins manylinux images instead')

-    if utils.IS_WINDOWS_RUNNING_ON_TRAVIS and python_version == '2.7':
+    if utils.platform == 'windows' and python_version == '2.7':
        pytest.skip('Windows + Travis CI requires a workaround')

    project_dir = tmp_path / 'project'
@@ -147,7 +153,7 @@ def test_dependency_constraints_file(tmp_path, python_version):
        build_environment[env_name] = version

    cibw_environment_option = ' '.join(
-        [f'{k}={v}' for k, v in build_environment.items()]
+        f'{k}={v}' for k, v in build_environment.items()
    )

    # build and test the wheels
@@ -7,7 +7,7 @@ from . import test_projects, utils

 dockcross_only_project = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(r'''
-        import os, sys
+        import os

        # check that we're running in the correct docker image as specified in the
        # environment options CIBW_MANYLINUX1_*_IMAGE
@@ -31,10 +31,10 @@ def test(tmp_path):
    actual_wheels = utils.cibuildwheel_run(project_dir, add_env={
        'CIBW_MANYLINUX_X86_64_IMAGE': 'dockcross/manylinux2010-x64',
        'CIBW_MANYLINUX_I686_IMAGE': 'dockcross/manylinux2010-x86',
-        'CIBW_SKIP': 'pp* cp39-*',
+        'CIBW_SKIP': 'pp* cp27-* cp39-*',
    })

    # also check that we got the right wheels built
    expected_wheels = [w for w in utils.expected_wheels('spam', '0.1.0')
-                       if '-pp' not in w and '-cp39-' not in w]
+                       if '-pp' not in w and '-cp39-' not in w and '-cp27-' not in w]
    assert set(actual_wheels) == set(expected_wheels)
@@ -0,0 +1,121 @@
+import platform
+import subprocess
+from typing import Tuple
+
+import pytest
+
+from . import test_projects, utils
+
+basic_project = test_projects.new_c_project()
+
+ALL_MACOS_WHEELS = (
+    utils.expected_wheels('spam', '0.1.0', machine_arch='x86_64')
+    + utils.expected_wheels('spam', '0.1.0', machine_arch='arm64')
+)
+
+
+def get_xcode_version() -> Tuple[int, int]:
+    output = subprocess.run(
+        ['xcodebuild', '-version'],
+        universal_newlines=True,
+        check=True,
+        stdout=subprocess.PIPE,
+    ).stdout
+    lines = output.splitlines()
+    _, version_str = lines[0].split()
+
+    version_parts = version_str.split('.')
+    return (int(version_parts[0]), int(version_parts[1]))
+
+
+def test_cross_compiled_build(tmp_path):
+    if utils.platform != 'macos':
+        pytest.skip('this test is only relevant to macos')
+    if get_xcode_version() < (12, 2):
+        pytest.skip('this test only works with Xcode 12.2 or greater')
+
+    project_dir = tmp_path / 'project'
+    basic_project.generate(project_dir)
+
+    actual_wheels = utils.cibuildwheel_run(project_dir, add_env={
+        'CIBW_BUILD': 'cp39-*',
+        'CIBW_ARCHS': 'x86_64, universal2, arm64',
+    })
+
+    expected_wheels = [w for w in ALL_MACOS_WHEELS if 'cp39' in w]
+    assert set(actual_wheels) == set(expected_wheels)
+
+
+@pytest.mark.parametrize('build_universal2', [False, True])
+def test_cross_compiled_test(tmp_path, capfd, build_universal2):
+    if utils.platform != 'macos':
+        pytest.skip('this test is only relevant to macos')
+    if get_xcode_version() < (12, 2):
+        pytest.skip('this test only works with Xcode 12.2 or greater')
+
+    project_dir = tmp_path / 'project'
+    basic_project.generate(project_dir)
+
+    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' if build_universal2 else 'x86_64 arm64',
+    })
+
+    captured = capfd.readouterr()
+
+    if platform.machine() == 'x86_64':
+        # ensure that tests were run on only x86_64
+        assert 'running tests on x86_64' in captured.out
+        assert 'running tests on arm64' not in captured.out
+        if build_universal2:
+            assert 'While universal2 wheels can be built on x86_64, the arm64 part of them cannot currently be tested' in captured.err
+        else:
+            assert 'While arm64 wheels can be built on x86_64, they cannot be tested' in captured.err
+    elif platform.machine() == 'arm64':
+        # ensure that tests were run on both x86_64 and arm64
+        assert 'running tests on x86_64' in captured.out
+        assert 'running tests on arm64' in captured.out
+
+    if build_universal2:
+        expected_wheels = [w for w in ALL_MACOS_WHEELS if 'cp39' in w and 'universal2' in w]
+    else:
+        expected_wheels = [w for w in ALL_MACOS_WHEELS if 'cp39' in w and 'universal2' not in w]
+
+    assert set(actual_wheels) == set(expected_wheels)
+
+
+@pytest.mark.parametrize('skip_arm64_test', [False, True])
+def test_universal2_testing(tmp_path, capfd, skip_arm64_test):
+    if utils.platform != 'macos':
+        pytest.skip('this test is only relevant to macos')
+    if get_xcode_version() < (12, 2):
+        pytest.skip('this test only works with Xcode 12.2 or greater')
+    if platform.machine() != 'x86_64':
+        pytest.skip('this test only works on x86_64')
+
+    project_dir = tmp_path / 'project'
+    basic_project.generate(project_dir)
+
+    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 '',
+    })
+
+    captured = capfd.readouterr()
+
+    if platform.machine() == 'x86_64':
+        assert 'running tests on x86_64' in captured.out
+        assert 'running tests on arm64' not in captured.out
+
+        warning_message = 'While universal2 wheels can be built on x86_64, the arm64 part of them cannot currently be tested'
+        if skip_arm64_test:
+            assert warning_message not in captured.err
+        else:
+            assert warning_message in captured.err
+
+    expected_wheels = [w for w in ALL_MACOS_WHEELS if 'cp39' in w and 'universal2' in w]
+
+    assert set(actual_wheels) == set(expected_wheels)
@@ -9,6 +9,9 @@ from . import test_projects, utils
 project_with_manylinux_symbols = test_projects.new_c_project(
    spam_c_top_level_add=textwrap.dedent(r'''
        #include <malloc.h>
+        #include <stdlib.h>
+        #include <stdint.h>
+        #include <math.h>

        #if !defined(__GLIBC_PREREQ)
        #error "Must run on a glibc linux environment"
@@ -19,19 +22,21 @@ project_with_manylinux_symbols = test_projects.new_c_project(
        #endif
    '''),
    spam_c_function_add=textwrap.dedent(r'''
-        #if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 17)  /* manylinux2014 is glibc 2.17 */
-            // secure_getenv is only available in manylinux2014, ensuring
-            // that only a manylinux2014 wheel is produced
-            secure_getenv("NON_EXISTING_ENV_VARIABLE");
+        #if defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 24)
+            // nextupf is only available in manylinux_2_24+
+            sts = (int)nextupf(0.0F);
+        #elif defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 17)  /* manylinux2014 is glibc 2.17 */
+            // secure_getenv is only available in manylinux2014+
+            sts = (int)(intptr_t)secure_getenv("NON_EXISTING_ENV_VARIABLE");
        #elif defined(__GLIBC_PREREQ) && __GLIBC_PREREQ(2, 10)  /* manylinux2010 is glibc 2.12 */
            // malloc_info is only available on manylinux2010+
-            malloc_info(0, stdout);
+            sts = malloc_info(0, stdout);
        #endif
    '''),
 )


-@pytest.mark.parametrize('manylinux_image', ['manylinux1', 'manylinux2010', 'manylinux2014'])
+@pytest.mark.parametrize('manylinux_image', ['manylinux1', 'manylinux2010', 'manylinux2014', 'manylinux_2_24'])
 def test(manylinux_image, tmp_path):
    if utils.platform != 'linux':
        pytest.skip('the docker test is only relevant to the linux build')
@@ -46,7 +51,7 @@ def test(manylinux_image, tmp_path):
    # CFLAGS environment variable is necessary to fail on 'malloc_info' (on manylinux1) during compilation/linking,
    # rather than when dynamically loading the Python
    add_env = {
-        'CIBW_ENVIRONMENT': 'CFLAGS="$CFLAGS -Werror=implicit-function-declaration"',
+        'CIBW_ENVIRONMENT': 'CFLAGS="$CFLAGS -O0 -Werror=implicit-function-declaration"',
        'CIBW_MANYLINUX_X86_64_IMAGE': manylinux_image,
        'CIBW_MANYLINUX_I686_IMAGE': manylinux_image,
        'CIBW_MANYLINUX_PYPY_X86_64_IMAGE': manylinux_image,
@@ -57,14 +62,14 @@ def test(manylinux_image, tmp_path):
    if manylinux_image == 'manylinux1':
        # We don't have a manylinux1 image for PyPy
        add_env['CIBW_SKIP'] = 'pp*'
-    elif manylinux_image == 'manylinux2014':
-        # We don't have a manylinux2014 image for PyPy (yet?)
-        add_env['CIBW_SKIP'] = 'cp27* pp*'  # Python 2.7 not available on manylinux2014
+    elif manylinux_image in {'manylinux2014', 'manylinux_2_24'}:
+        # We don't have a manylinux2014 / 'manylinux_2_24' image for PyPy (yet?)
+        add_env['CIBW_SKIP'] = 'cp27* pp*'  # Python 2.7 not available on manylinux2014 / 'manylinux_2_24'
    actual_wheels = utils.cibuildwheel_run(project_dir, add_env=add_env)

    expected_wheels = [w for w in utils.expected_wheels('spam', '0.1.0', manylinux_versions=[manylinux_image])]
-    if manylinux_image == 'manylinux2014':
+    if manylinux_image in {'manylinux2014', 'manylinux_2_24'}:
        expected_wheels = [w for w in expected_wheels if '-cp27' not in w]
-    if manylinux_image in ['manylinux1', 'manylinux2014']:
+    if manylinux_image in {'manylinux1', 'manylinux2014', 'manylinux_2_24'}:
        expected_wheels = [w for w in expected_wheels if '-pp' not in w]
    assert set(actual_wheels) == set(expected_wheels)
@@ -7,7 +7,6 @@ basic_project = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(
        """
        # Will fail if PEP 518 does work
-        import sys
        import requests
        if sys.version_info < (3, 6, 0):
            assert requests.__version__ == "2.22.0", "Requests found but wrong version ({0})".format(requests.__version__)
@@ -34,11 +34,11 @@ def main():

    if options.open:
        if sys.platform == 'darwin':
-            subprocess.check_call(['open', '--', project_dir])
+            subprocess.run(['open', '--', project_dir], check=True)
        elif sys.platform == 'linux2':
-            subprocess.check_call(['xdg-open', '--', project_dir])
+            subprocess.run(['xdg-open', '--', project_dir], check=True)
        elif sys.platform == 'win32':
-            subprocess.check_call(['explorer', project_dir])
+            subprocess.run(['explorer', project_dir], check=True)


 if __name__ == '__main__':
@@ -60,12 +60,21 @@ MOD_INIT(spam)
 '''

 SETUP_PY_TEMPLATE = r'''
+import sys
 from setuptools import setup, Extension

 {{ setup_py_add }}

+libraries = []
+if sys.platform.startswith('linux'):
+    libraries.extend(['m', 'c'])
+
 setup(
-    ext_modules=[Extension('spam', sources=['spam.c'])],
+    ext_modules=[Extension(
+        'spam',
+        sources=['spam.c'],
+        libraries=libraries,
+    )],
    {{ setup_py_setup_args_add | indent(4) }}
 )
 '''
@@ -5,7 +5,6 @@ from . import test_projects, utils
 project_with_ssl_tests = test_projects.new_c_project(
    setup_py_add=textwrap.dedent(r'''
        import ssl
-        import sys

        if sys.version_info[0] == 2:
            from urllib2 import urlopen
@@ -10,11 +10,20 @@ import shutil
 import subprocess
 import sys
 from contextlib import contextmanager
-from pathlib import Path
 from tempfile import mkdtemp

-IS_WINDOWS_RUNNING_ON_AZURE = Path('C:\\hostedtoolcache').exists()
-IS_WINDOWS_RUNNING_ON_TRAVIS = os.environ.get('TRAVIS_OS_NAME') == 'windows'
+platform: str
+
+if 'CIBW_PLATFORM' in os.environ:
+    platform = os.environ['CIBW_PLATFORM']
+elif sys.platform.startswith('linux'):
+    platform = 'linux'
+elif sys.platform.startswith('darwin'):
+    platform = 'macos'
+elif sys.platform in ['win32', 'cygwin']:
+    platform = 'windows'
+else:
+    raise Exception('Unsupported platform')


 # Python 2 does not have a tempfile.TemporaryDirectory context manager
@@ -33,11 +42,13 @@ def cibuildwheel_get_build_identifiers(project_path, env=None):
    Returns the list of build identifiers that cibuildwheel will try to build
    for the current platform.
    '''
-    cmd_output = subprocess.check_output(
+    cmd_output = subprocess.run(
        [sys.executable, '-m', 'cibuildwheel', '--print-build-identifiers', str(project_path)],
        universal_newlines=True,
        env=env,
-    )
+        check=True,
+        stdout=subprocess.PIPE,
+    ).stdout

    return cmd_output.strip().split('\n')

@@ -66,18 +77,32 @@ def cibuildwheel_run(project_path, package_dir='.', env=None, add_env=None, outp
        env.update(add_env)

    with TemporaryDirectoryIfNone(output_dir) as _output_dir:
-        subprocess.check_call(
+        subprocess.run(
            [sys.executable, '-m', 'cibuildwheel', '--output-dir', str(_output_dir), str(package_dir)],
            env=env,
            cwd=project_path,
+            check=True,
        )
        wheels = os.listdir(_output_dir)
    return wheels


+def _get_arm64_macosx_deployment_target(macosx_deployment_target: 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.
+    '''
+    version_tuple = tuple(map(int, macosx_deployment_target.split('.')))
+    if version_tuple <= (11, 0):
+        return '11.0'
+    else:
+        return macosx_deployment_target
+
+
 def expected_wheels(package_name, package_version, manylinux_versions=None,
                    macosx_deployment_target='10.9', machine_arch=None, *,
-                    exclude_27=IS_WINDOWS_RUNNING_ON_TRAVIS):
+                    exclude_27=platform == 'windows'):
    '''
    Returns a list of expected wheels from a run of cibuildwheel.
    '''
@@ -103,6 +128,17 @@ def expected_wheels(package_name, package_version, manylinux_versions=None,
        if platform == 'linux':
            python_abi_tags.append('cp27-cp27mu')  # python 2.7 has 2 different ABI on manylinux

+    if platform == 'macos' and get_macos_version() >= (10, 16):
+        # 10.16 is sometimes reported as the macOS version on macOS 11.
+        # CPython 3.5 doesn't work on macOS 11.
+        python_abi_tags.remove('cp35-cp35m')
+        # pypy not supported on macOS 11.
+        python_abi_tags = [t for t in python_abi_tags if not t.startswith('pp')]
+
+    if platform == 'macos' and machine_arch == 'arm64':
+        # currently, arm64 macs are only supported by cp39
+        python_abi_tags = ['cp39-cp39']
+
    wheels = []

    for python_abi_tag in python_abi_tags:
@@ -127,7 +163,16 @@ def expected_wheels(package_name, package_version, manylinux_versions=None,
                platform_tags = ['win32']

        elif platform == 'macos':
-            platform_tags = [f'macosx_{macosx_deployment_target.replace(".", "_")}_x86_64']
+            if python_abi_tag == 'cp39-cp39' and machine_arch == 'arm64':
+                arm64_macosx_deployment_target = _get_arm64_macosx_deployment_target(macosx_deployment_target)
+                platform_tags = [
+                    f'macosx_{macosx_deployment_target.replace(".", "_")}_universal2',
+                    f'macosx_{arm64_macosx_deployment_target.replace(".", "_")}_arm64',
+                ]
+            else:
+                platform_tags = [
+                    f'macosx_{macosx_deployment_target.replace(".", "_")}_x86_64',
+                ]

        else:
            raise Exception('unsupported platform')
@@ -143,15 +188,13 @@ def expected_wheels(package_name, package_version, manylinux_versions=None,
    return wheels


-platform = None
+def get_macos_version():
+    '''
+    Returns the macOS major/minor version, as a tuple, e.g. (10, 15) or (11, 0)

-if 'CIBW_PLATFORM' in os.environ:
-    platform = os.environ['CIBW_PLATFORM']
-elif sys.platform.startswith('linux'):
-    platform = 'linux'
-elif sys.platform.startswith('darwin'):
-    platform = 'macos'
-elif sys.platform in ['win32', 'cygwin']:
-    platform = 'windows'
-else:
-    raise Exception('Unsupported platform')
+    These tuples can be used in comparisons, e.g.
+        (10, 14) <= (11, 0) == True
+        (11, 2) <= (11, 0) != True
+    '''
+    version_str, _, _ = pm.mac_ver()
+    return tuple(map(int, version_str.split(".")[:2]))
@@ -1,11 +1,8 @@
-import pytest
 import toml
-
-from cibuildwheel.util import resources_dir
-
-Version = pytest.importorskip("packaging.version").Version
+from packaging.version import Version

 from cibuildwheel.extra import InlineArrayDictEncoder  # noqa: E402
+from cibuildwheel.util import resources_dir


 def test_compare_configs():
@@ -1,3 +1,5 @@
+from packaging.specifiers import SpecifierSet
+
 from cibuildwheel.util import BuildSelector


@@ -69,3 +71,36 @@ def test_build_braces():
    assert build_selector('cp37-manylinux1_x86_64')
    assert not build_selector('cp38-manylinux1_x86_64')
    assert not build_selector('cp39-manylinux1_x86_64')
+
+
+def test_build_limited_python():
+    build_selector = BuildSelector(build_config="*", skip_config="", requires_python=SpecifierSet(">=3.6"))
+
+    assert not build_selector('cp27-manylinux1_x86_64')
+    assert build_selector('cp36-manylinux1_x86_64')
+    assert build_selector('cp37-manylinux1_x86_64')
+    assert not build_selector('cp27-manylinux1_i686')
+    assert build_selector('cp36-manylinux1_i686')
+    assert build_selector('cp37-manylinux1_i686')
+    assert not build_selector('cp27-win32')
+    assert build_selector('cp36-win32')
+    assert build_selector('cp37-win32')
+    assert not build_selector('pp27-win32')
+    assert build_selector('pp36-win32')
+    assert build_selector('pp37-win32')
+
+
+def test_build_limited_python_partial():
+    build_selector = BuildSelector(build_config="*", skip_config="", requires_python=SpecifierSet(">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*"))
+
+    assert build_selector('cp27-manylinux1_x86_64')
+    assert not build_selector('cp35-manylinux1_x86_64')
+    assert build_selector('cp36-manylinux1_x86_64')
+
+
+def test_build_limited_python_patch():
+    build_selector = BuildSelector(build_config="*", skip_config="", requires_python=SpecifierSet(">=2.7.9"))
+
+    assert build_selector('cp27-manylinux1_x86_64')
+    assert build_selector('cp36-manylinux1_x86_64')
+    assert build_selector('cp37-manylinux1_x86_64')
@@ -94,7 +94,7 @@ def test_binary_output():

        data = bytes(output, encoding='utf8', errors='surrogateescape')

-        for i in range(0, 512):
+        for i in range(512):
            assert data[i] == i % 256

        # check that environment variables can carry binary data, except null characters
@@ -1,3 +1,4 @@
+import contextlib
 import platform as platform_module
 import subprocess
 import sys
@@ -58,6 +59,15 @@ def fake_package_dir(monkeypatch):
    return args


+@pytest.fixture(autouse=True)
+def disable_print_wheels(monkeypatch):
+    @contextlib.contextmanager
+    def empty_cm(*args, **kwargs):
+        yield
+
+    monkeypatch.setattr(util, 'print_new_wheels', empty_cm)
+
+
@pytest.fixture
 def allow_empty(request, monkeypatch, fake_package_dir):
    monkeypatch.setattr(sys, 'argv', fake_package_dir + ['--allow-empty'])
@@ -73,6 +83,9 @@ def platform(request, monkeypatch):
    else:
        monkeypatch.setattr(platform_module, 'machine', lambda: 'x86_64')

+    if platform_value == 'macos':
+        monkeypatch.setattr(macos, 'get_macos_version', lambda: (11, 1))
+
    return platform_value


@@ -51,8 +51,8 @@ def test_build_selector(platform, intercepted_build_args, monkeypatch, allow_emp

    intercepted_build_selector = intercepted_build_args.args[0].build_selector
    assert isinstance(intercepted_build_selector, BuildSelector)
-    assert intercepted_build_selector('build-this')
-    assert not intercepted_build_selector('skip-that')
+    assert intercepted_build_selector('build24-this')
+    assert not intercepted_build_selector('skip65-that')
    # This unit test is just testing the options of 'main'
    # Unit tests for BuildSelector are in build_selector_test.py

@@ -71,11 +71,13 @@ def test_empty_selector(platform, intercepted_build_args, monkeypatch):
    ('x86_64', 'manylinux1', 'quay.io/pypa/manylinux1_x86_64:*'),
    ('x86_64', 'manylinux2010', 'quay.io/pypa/manylinux2010_x86_64:*'),
    ('x86_64', 'manylinux2014', 'quay.io/pypa/manylinux2014_x86_64:*'),
+    ('x86_64', 'manylinux_2_24', 'quay.io/pypa/manylinux_2_24_x86_64:*'),
    ('x86_64', 'custom_image', 'custom_image'),
    ('i686', None, 'quay.io/pypa/manylinux2010_i686:*'),
    ('i686', 'manylinux1', 'quay.io/pypa/manylinux1_i686:*'),
    ('i686', 'manylinux2010', 'quay.io/pypa/manylinux2010_i686:*'),
    ('i686', 'manylinux2014', 'quay.io/pypa/manylinux2014_i686:*'),
+    ('i686', 'manylinux_2_24', 'quay.io/pypa/manylinux_2_24_i686:*'),
    ('i686', 'custom_image', 'custom_image'),
    ('pypy_x86_64', None, 'pypywheels/manylinux2010-pypy_x86_64:*'),
    ('pypy_x86_64', 'manylinux1', 'manylinux1'),  # Does not exist
@@ -102,7 +104,7 @@ def get_default_repair_command(platform):
    if platform == 'linux':
        return 'auditwheel repair -w {dest_dir} {wheel}'
    elif platform == 'macos':
-        return 'delocate-listdeps {wheel} && delocate-wheel --require-archs x86_64 -w {dest_dir} {wheel}'
+        return 'delocate-listdeps {wheel} && delocate-wheel --require-archs {delocate_archs} -w {dest_dir} {wheel}'
    elif platform == 'windows':
        return ''
    else:
@@ -132,7 +134,7 @@ def test_repair_command(repair_command, platform_specific, platform, intercepted
 ])
@pytest.mark.parametrize('platform_specific', [False, True])
 def test_environment(environment, platform_specific, platform, intercepted_build_args, monkeypatch):
-    env_string = ' '.join([f'{k}={v}' for k, v in environment.items()])
+    env_string = ' '.join(f'{k}={v}' for k, v in environment.items())
    if platform_specific:
        monkeypatch.setenv('CIBW_ENVIRONMENT_' + platform.upper(), env_string)
        monkeypatch.setenv('CIBW_ENVIRONMENT', 'overwritten')
@@ -1,10 +1,11 @@
 import sys

 import pytest
-from conftest import MOCK_PACKAGE_DIR  # noqa: I100

 from cibuildwheel.__main__ import main
-from cibuildwheel.util import Architecture
+from cibuildwheel.architecture import Architecture
+
+from .conftest import MOCK_PACKAGE_DIR


 def test_unknown_platform_non_ci(monkeypatch, capsys):
@@ -122,12 +123,41 @@ def test_archs_platform_native(platform, intercepted_build_args, monkeypatch):
    main()
    build_options = intercepted_build_args.args[0]

-    if platform == 'linux':
+    if platform in {'linux', 'macos'}:
        assert build_options.architectures == {Architecture.x86_64}
    elif platform == 'windows':
        assert build_options.architectures == {Architecture.AMD64}
-    elif platform == 'macos':
+
+
+def test_archs_platform_auto64(platform, intercepted_build_args, monkeypatch):
+    monkeypatch.setenv('CIBW_ARCHS', 'auto64')
+
+    main()
+    build_options = intercepted_build_args.args[0]
+
+    if platform in {'linux', 'macos'}:
        assert build_options.architectures == {Architecture.x86_64}
+    elif platform == 'windows':
+        assert build_options.architectures == {Architecture.AMD64}
+
+
+def test_archs_platform_auto32(platform, intercepted_build_args, monkeypatch):
+    monkeypatch.setenv('CIBW_ARCHS', 'auto32')
+
+    if platform == 'macos':
+        with pytest.raises(SystemExit) as exit:
+            main()
+        assert exit.value.args == (4,)
+
+    else:
+        main()
+
+        build_options = intercepted_build_args.args[0]
+
+        if platform == 'linux':
+            assert build_options.architectures == {Architecture.i686}
+        elif platform == 'windows':
+            assert build_options.architectures == {Architecture.x86}


 def test_archs_platform_all(platform, intercepted_build_args, monkeypatch):
@@ -141,4 +171,4 @@ def test_archs_platform_all(platform, intercepted_build_args, monkeypatch):
    elif platform == 'windows':
        assert build_options.architectures == {Architecture.x86, Architecture.AMD64}
    elif platform == 'macos':
-        assert build_options.architectures == {Architecture.x86_64}
+        assert build_options.architectures == {Architecture.x86_64, Architecture.arm64, Architecture.universal2}
@@ -0,0 +1,103 @@
+import sys
+import textwrap
+
+import pytest
+from packaging.specifiers import SpecifierSet
+
+from cibuildwheel.__main__ import main
+
+
+@pytest.fixture(autouse=True, scope="function")
+def fake_package_dir(monkeypatch, tmp_path):
+    '''
+    Set up a fake project
+    '''
+
+    local_path = tmp_path / "tmp_project"
+    local_path.mkdir()
+
+    local_path.joinpath("setup.py").touch()
+
+    monkeypatch.setattr(sys, 'argv', ['cibuildwheel', str(local_path)])
+
+    return local_path
+
+
+def test_no_override(platform, monkeypatch, intercepted_build_args):
+
+    main()
+
+    intercepted_build_selector = intercepted_build_args.args[0].build_selector
+
+    assert intercepted_build_selector('cp39-win32')
+    assert intercepted_build_selector('cp36-win32')
+
+    assert intercepted_build_selector.requires_python is None
+
+
+def test_override_env(platform, monkeypatch, intercepted_build_args):
+    monkeypatch.setenv('CIBW_PROJECT_REQUIRES_PYTHON', '>=3.8')
+
+    main()
+
+    intercepted_build_selector = intercepted_build_args.args[0].build_selector
+
+    assert intercepted_build_selector.requires_python == SpecifierSet(">=3.8")
+
+    assert intercepted_build_selector('cp39-win32')
+    assert not intercepted_build_selector('cp36-win32')
+
+
+def test_override_setup_cfg(platform, monkeypatch, intercepted_build_args, fake_package_dir):
+
+    fake_package_dir.joinpath("setup.cfg").write_text(textwrap.dedent("""
+        [options]
+        python_requires = >=3.8
+    """))
+
+    main()
+
+    intercepted_build_selector = intercepted_build_args.args[0].build_selector
+
+    assert intercepted_build_selector.requires_python == SpecifierSet(">=3.8")
+
+    assert intercepted_build_selector('cp39-win32')
+    assert not intercepted_build_selector('cp36-win32')
+
+
+def test_override_pyproject_toml(platform, monkeypatch, intercepted_build_args, fake_package_dir):
+
+    fake_package_dir.joinpath("pyproject.toml").write_text(textwrap.dedent("""
+        [project]
+        requires-python = ">=3.8"
+    """))
+
+    main()
+
+    intercepted_build_selector = intercepted_build_args.args[0].build_selector
+
+    assert intercepted_build_selector.requires_python == SpecifierSet(">=3.8")
+
+    assert intercepted_build_selector('cp39-win32')
+    assert not intercepted_build_selector('cp36-win32')
+
+
+def test_override_setup_py_simple(platform, monkeypatch, intercepted_build_args, fake_package_dir):
+
+    fake_package_dir.joinpath("setup.py").write_text(textwrap.dedent("""
+        from setuptools import setup
+
+        setup(
+            name = "other",
+            python_requires = ">=3.7",
+        )
+    """))
+
+    main()
+
+    intercepted_build_selector = intercepted_build_args.args[0].build_selector
+
+    assert intercepted_build_selector.requires_python == SpecifierSet(">=3.7")
+
+    assert intercepted_build_selector('cp39-win32')
+    assert not intercepted_build_selector('cp36-win32')
@@ -0,0 +1,142 @@
+from textwrap import dedent
+
+from cibuildwheel.projectfiles import get_requires_python_str, setup_py_python_requires
+
+
+def test_read_setup_py_simple(tmp_path):
+    with open(tmp_path / "setup.py", "w") as f:
+        f.write(dedent("""
+            from setuptools import setup
+
+            setup(
+                name = "hello",
+                other = 23,
+                example = ["item", "other"],
+                python_requires = "1.23",
+            )
+            """))
+
+    assert setup_py_python_requires(tmp_path.joinpath("setup.py").read_text()) == "1.23"
+    assert get_requires_python_str(tmp_path) == "1.23"
+
+
+def test_read_setup_py_full(tmp_path):
+    with open(tmp_path / "setup.py", "w") as f:
+        f.write(dedent("""
+            import setuptools
+
+            setuptools.randomfunc()
+
+            setuptools.setup(
+                name = "hello",
+                other = 23,
+                example = ["item", "other"],
+                python_requires = "1.24",
+            )
+            """))
+
+    assert setup_py_python_requires(tmp_path.joinpath("setup.py").read_text()) == "1.24"
+    assert get_requires_python_str(tmp_path) == "1.24"
+
+
+def test_read_setup_py_assign(tmp_path):
+    with open(tmp_path / "setup.py", "w") as f:
+        f.write(dedent("""
+            from setuptools import setup
+
+            REQUIRES = "3.21"
+
+            setuptools.setup(
+                name = "hello",
+                other = 23,
+                example = ["item", "other"],
+                python_requires = REQUIRES,
+            )
+            """))
+
+    assert setup_py_python_requires(tmp_path.joinpath("setup.py").read_text()) is None
+    assert get_requires_python_str(tmp_path) is None
+
+
+def test_read_setup_py_None(tmp_path):
+    with open(tmp_path / "setup.py", "w") as f:
+        f.write(dedent("""
+            from setuptools import setup
+
+            REQUIRES = None
+
+            setuptools.setup(
+                name = "hello",
+                other = 23,
+                example = ["item", "other"],
+                python_requires = None,
+            )
+            """))
+
+    assert setup_py_python_requires(tmp_path.joinpath("setup.py").read_text()) is None
+    assert get_requires_python_str(tmp_path) is None
+
+
+def test_read_setup_py_empty(tmp_path):
+    with open(tmp_path / "setup.py", "w") as f:
+        f.write(dedent("""
+            from setuptools import setup
+
+            REQUIRES = "3.21"
+
+            setuptools.setup(
+                name = "hello",
+                other = 23,
+                example = ["item", "other"],
+            )
+            """))
+
+    assert setup_py_python_requires(tmp_path.joinpath("setup.py").read_text()) is None
+    assert get_requires_python_str(tmp_path) is None
+
+
+def test_read_setup_cfg(tmp_path):
+    with open(tmp_path / "setup.cfg", "w") as f:
+        f.write(dedent("""
+            [options]
+            python_requires = 1.234
+            [metadata]
+            something = other
+            """))
+
+    assert get_requires_python_str(tmp_path) == "1.234"
+
+
+def test_read_setup_cfg_empty(tmp_path):
+    with open(tmp_path / "setup.cfg", "w") as f:
+        f.write(dedent("""
+            [options]
+            other = 1.234
+            [metadata]
+            something = other
+            """))
+
+    assert get_requires_python_str(tmp_path) is None
+
+
+def test_read_pyproject_toml(tmp_path):
+    with open(tmp_path / "pyproject.toml", "w") as f:
+        f.write(dedent("""
+            [project]
+            requires-python = "1.654"
+
+            [tool.cibuildwheel]
+            something = "other"
+            """))
+
+    assert get_requires_python_str(tmp_path) == "1.654"
+
+
+def test_read_pyproject_toml_empty(tmp_path):
+    with open(tmp_path / "pyproject.toml", "w") as f:
+        f.write(dedent("""
+            [project]
+            other = 1.234
+            """))
+
+    assert get_requires_python_str(tmp_path) is None
@@ -0,0 +1,35 @@
+import pytest
+
+from cibuildwheel.util import print_new_wheels
+
+
+def test_printout_wheels(tmp_path, capsys):
+    tmp_path.joinpath("example.0").touch()
+    with print_new_wheels("TEST_MSG: {n}", tmp_path):
+        tmp_path.joinpath("example.1").touch()
+        tmp_path.joinpath("example.2").touch()
+
+    captured = capsys.readouterr()
+    assert captured.err == ""
+
+    assert "example.0" not in captured.out
+    assert "example.1\n" in captured.out
+    assert "example.2\n" in captured.out
+    assert "TEST_MSG:" in captured.out
+    assert "TEST_MSG: 2\n" in captured.out
+
+
+def test_no_printout_on_error(tmp_path, capsys):
+    tmp_path.joinpath("example.0").touch()
+    with pytest.raises(RuntimeError):
+        with print_new_wheels("TEST_MSG: {n}", tmp_path):
+            tmp_path.joinpath("example.1").touch()
+            raise RuntimeError()
+
+    captured = capsys.readouterr()
+    assert captured.err == ""
+
+    assert "example.0" not in captured.out
+    assert "example.1" not in captured.out
+    assert "example.2" not in captured.out
+    assert "TEST_MSG:" not in captured.out