Add support for building Android wheels

.github/workflows/test.yml

@@ -70,13 +70,23 @@ jobs:
 
     - uses: astral-sh/setup-uv@v6
 
-    # free some space to prevent reaching GHA disk space limits
-    - name: Clean docker images
+    - name: Free up disk space
       if: runner.os == 'Linux'
       run: |
         docker system prune -a -f
+        sudo rm -rf $ANDROID_HOME/ndk/{26,28}.* /opt/hostedtoolcache/CodeQL \
+          /usr/local/lib/node_modules /usr/local/share/chromium \
+          /usr/local/share/powershell
         df -h
 
+    # https://github.blog/changelog/2024-04-02-github-actions-hardware-accelerated-android-virtualization-now-available/
+    - name: Enable KVM for Android emulator
+      if: runner.os == 'Linux' && runner.arch == 'X64'
+      run: |
+          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' | sudo tee /etc/udev/rules.d/99-kvm4all.rules
+          sudo udevadm control --reload-rules
+          sudo udevadm trigger --name-match=kvm
+
     # for oci_container unit tests
     - name: Set up QEMU
       if: runner.os == 'Linux'

.pre-commit-config.yaml

@@ -26,13 +26,16 @@ repos:
   - id: mypy
     name: mypy 3.11 on cibuildwheel/
     args: ["--python-version=3.11"]
+    exclude: ^cibuildwheel/resources/_cross_venv.py$  # Requires Python 3.13 or later
     additional_dependencies: &mypy-dependencies
       - bracex
+      - build
       - dependency-groups>=1.2
       - humanize
       - nox>=2025.2.9
       - orjson
       - packaging
+      - pyelftools
       - pygithub
       - pytest
       - rich
@@ -47,7 +50,6 @@ repos:
       - validate-pyproject
   - id: mypy
     name: mypy 3.13
-    exclude: ^cibuildwheel/resources/.*py$
     args: ["--python-version=3.13"]
     additional_dependencies: *mypy-dependencies
 

README.md

@@ -23,20 +23,20 @@ What does it do?
 
 While cibuildwheel itself requires a recent Python version to run (we support the last three releases), it can target the following versions to build wheels:
 
-|                    | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | Windows Arm64 | manylinux<br/>musllinux x86_64 | manylinux<br/>musllinux i686 | manylinux<br/>musllinux aarch64 | manylinux<br/>musllinux ppc64le | manylinux<br/>musllinux s390x | manylinux<br/>musllinux armv7l | iOS | Pyodide |
-|--------------------|----|-----|-----|-----|-----|----|-----|----|-----|-----|---|-----|-----|
-| CPython 3.8        | ✅ | ✅  | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A |
-| CPython 3.9        | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅ | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A |
-| CPython 3.10       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A |
-| CPython 3.11       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A |
-| CPython 3.12       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | N/A | ✅⁴ |
-| CPython 3.13³      | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | ✅ | N/A |
-| CPython 3.14³      | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | ✅ | N/A |
-| PyPy 3.8 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A |
-| PyPy 3.9 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A |
-| PyPy 3.10 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A |
-| PyPy 3.11 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A |
-| GraalPy 3.11 v24.2 | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | N/A  | ✅¹ | N/A | N/A | N/A | N/A | N/A |
+|                    | macOS Intel | macOS Apple Silicon | Windows 64bit | Windows 32bit | Windows Arm64 | manylinux<br/>musllinux x86_64 | manylinux<br/>musllinux i686 | manylinux<br/>musllinux aarch64 | manylinux<br/>musllinux ppc64le | manylinux<br/>musllinux s390x | manylinux<br/>musllinux armv7l | Android | iOS | Pyodide |
+|--------------------|----|-----|----|-----|-----|----|-----|----|-----|-----|---|-----|-----|-----|
+| CPython 3.8        | ✅ | ✅  | ✅  | ✅  | N/A | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
+| CPython 3.9        | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅ | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
+| CPython 3.10       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
+| CPython 3.11       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵ | N/A | N/A | N/A |
+| CPython 3.12       | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | N/A | N/A | ✅⁴ |
+| CPython 3.13³      | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | ✅ | ✅ | N/A |
+| CPython 3.14³      | ✅ | ✅  | ✅  | ✅  | ✅² | ✅ | ✅  | ✅ | ✅  | ✅  | ✅⁵  | N/A | N/A | N/A |
+| PyPy 3.8 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
+| PyPy 3.9 v7.3      | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
+| PyPy 3.10 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
+| PyPy 3.11 v7.3     | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | ✅¹  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
+| GraalPy 3.11 v24.2 | ✅ | ✅  | ✅  | N/A | N/A | ✅¹ | N/A  | ✅¹ | N/A | N/A | N/A | N/A | N/A | N/A |
 
 <sup>¹ PyPy & GraalPy are only supported for manylinux wheels.</sup><br>
 <sup>² Windows arm64 support is experimental.</sup><br>
@@ -56,19 +56,19 @@ Usage
 
 `cibuildwheel` runs inside a CI service. Supported platforms depend on which service you're using:
 
-|                 | Linux | macOS | Windows | Linux ARM | macOS ARM | Windows ARM | iOS |
-|-----------------|-------|-------|---------|-----------|-----------|-------------|-----|
-| GitHub Actions  | ✅    | ✅    | ✅       | ✅        | ✅        | ✅          | ✅³  |
-| Azure Pipelines | ✅    | ✅    | ✅       |           | ✅        | ✅²         | ✅³  |
-| Travis CI       | ✅    |       | ✅      | ✅        |           |             |     |
-| CircleCI        | ✅    | ✅    |         | ✅        | ✅        |             | ✅³  |
-| Gitlab CI       | ✅    | ✅    | ✅      | ✅¹       | ✅        |             | ✅³  |
-| Cirrus CI       | ✅    | ✅    | ✅      | ✅        | ✅        |             |      |
+|                 | Linux | macOS | Windows | Linux ARM | macOS ARM | Windows ARM | Android | iOS |
+|-----------------|-------|-------|---------|-----------|-----------|-------------|---------|-----|
+| GitHub Actions  | ✅    | ✅    | ✅       | ✅        | ✅        | ✅²         | ✅⁴      | ✅³  |
+| Azure Pipelines | ✅    | ✅    | ✅       |           | ✅        | ✅²         | ✅⁴      | ✅³  |
+| Travis CI       | ✅    |       | ✅      | ✅        |           |             | ✅⁴      |     |
+| CircleCI        | ✅    | ✅    |         | ✅        | ✅        |             | ✅⁴      | ✅³  |
+| Gitlab CI       | ✅    | ✅    | ✅      | ✅¹       | ✅        |             | ✅⁴      | ✅³  |
+| Cirrus CI       | ✅    | ✅    | ✅      | ✅        | ✅        |             | ✅⁴      |      |
 
 <sup>¹ [Requires emulation](https://cibuildwheel.pypa.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>
 <sup>² [Uses cross-compilation](https://cibuildwheel.pypa.io/en/stable/faq/#windows-arm64). It is not possible to test `arm64` on this CI platform.</sup><br>
-<sup>³ Requires a macOS runner; runs tests on the simulator for the runner's architecture.</sup>
-
+<sup>³ Requires a macOS runner; runs tests on the simulator for the runner's architecture.</sup><br>
+<sup>⁴ Building for Android requires the runner to be Linux x86_64, macOS ARM64 or macOS x86_64. Testing has [additional requirements](https://cibuildwheel.pypa.io/en/stable/platforms/#android).</sup><br>
 <!--intro-end-->
 
 Example setup
@@ -151,7 +151,7 @@ The following diagram summarises the steps that cibuildwheel takes on each platf
 |  | [`pyodide-version`](https://cibuildwheel.pypa.io/en/stable/options/#pyodide-version) | Specify the Pyodide version to use for `pyodide` platform builds |
 | **Testing** | [`test-command`](https://cibuildwheel.pypa.io/en/stable/options/#test-command) | The command to test each built wheel |
 |  | [`before-test`](https://cibuildwheel.pypa.io/en/stable/options/#before-test) | Execute a shell command before testing each wheel |
-|  | [`test-sources`](https://cibuildwheel.pypa.io/en/stable/options/#test-sources) | Files and folders from the source tree that are copied into an isolated tree before running the tests |
+|  | [`test-sources`](https://cibuildwheel.pypa.io/en/stable/options/#test-sources) | Paths that are copied into the working directory of the tests |
 |  | [`test-requires`](https://cibuildwheel.pypa.io/en/stable/options/#test-requires) | Install Python dependencies before running the tests |
 |  | [`test-extras`](https://cibuildwheel.pypa.io/en/stable/options/#test-extras) | Install your wheel for testing using `extras_require` |
 |  | [`test-groups`](https://cibuildwheel.pypa.io/en/stable/options/#test-groups) | Specify test dependencies from your project's `dependency-groups` |
@@ -162,7 +162,7 @@ The following diagram summarises the steps that cibuildwheel takes on each platf
 |  | [`build-verbosity`](https://cibuildwheel.pypa.io/en/stable/options/#build-verbosity) | Increase/decrease the output of the build |
 
 
-<!--[[[end]]] (sum: TWqEGGMOnt) -->
+<!--[[[end]]] (sum: FxE3nIgFiY) -->
 
 These options can be specified in a pyproject.toml file, or as environment variables, see [configuration docs](https://cibuildwheel.pypa.io/en/latest/configuration/).
 
@@ -245,10 +245,10 @@ See @henryiii's [release post](https://iscinumpy.dev/post/cibuildwheel-3-0-0/) f
 - ✨ Adds CPython 3.14 support, under the [`enable` option](https://cibuildwheel.pypa.io/en/stable/options/#enable) `cpython-prerelease`. This version of cibuildwheel uses 3.14.0b2. (#2390)
 
     _While CPython is in beta, the ABI can change, so your wheels might not be compatible with the final release. For this reason, we don't recommend distributing wheels until RC1, at which point 3.14 will be available in cibuildwheel without the flag._ (#2390)
-- ✨ Adds the [test-sources option](https://cibuildwheel.pypa.io/en/stable/options/#test-sources), and changes the working directory for tests. (#2062, #2284, #2437)
 
-    - If this option is set, cibuildwheel will copy the files and folders specified in `test-sources` into the temporary directory we run from. This is required for iOS builds, but also useful for other platforms, as it allows you to avoid placeholders.
-    - If this option is not set, behaviour matches v2.x - cibuildwheel will run the tests from a temporary directory, and you can use the `{project}` placeholder in the `test-command` to refer to the project directory. (#2420)
+- ✨ Adds the [test-sources option](https://cibuildwheel.pypa.io/en/stable/options/#test-sources), which copies files and folders into the temporary working directory we run tests from. (#2062, #2284, #2420, #2437)
+
+    This is particularly important for iOS builds, which do not support placeholders in the `test-command`, but can also be useful for other platforms.
 
 - ✨ Adds [`dependency-versions`](https://cibuildwheel.pypa.io/en/stable/options/#dependency-versions) inline syntax (#2122)
 - ✨ Improves support for Pyodide builds and adds the experimental [`pyodide-version`](https://cibuildwheel.pypa.io/en/stable/options/#pyodide-version) option, which allows you to specify the version of Pyodide to use for builds. (#2002)
@@ -292,7 +292,7 @@ _15 March 2025_
 - ⚠️ Added warnings when the shorthand values `manylinux1`, `manylinux2010`, `manylinux_2_24`, and `musllinux_1_1` are used to specify the images in linux builds. The shorthand to these (unmaintainted) images will be removed in v3.0. If you want to keep using these images, explicitly opt-in using the full image URL, which can be found in [this file](https://github.com/pypa/cibuildwheel/blob/v2.23.1/cibuildwheel/resources/pinned_docker_images.cfg). (#2312)
 - 🛠 Dependency updates, including a manylinux update which fixes an [issue with rustup](https://github.com/pypa/cibuildwheel/issues/2303). (#2315)
 
-<!-- [[[end]]] (sum: QKx9Hx5znR) -->
+<!-- [[[end]]] (sum: fBN/s9Yq6D) -->
 
 ---
 

azure-pipelines.yml

@@ -23,6 +23,11 @@ jobs:
     - task: UsePythonVersion@0
       inputs:
         versionSpec: '3.11'
+    - task: JavaToolInstaller@0
+      inputs:
+        versionSpec: '17'
+        jdkArchitectureOption: 'x64'
+        jdkSourceOption: 'PreInstalled'
     - bash: |
         docker run --rm --privileged docker.io/tonistiigi/binfmt:latest --install all
         python -m pip install -U pip

bin/generate_schema.py

@@ -348,6 +348,7 @@ def as_object(d: dict[str, Any]) -> dict[str, Any]:
     "windows": as_object(not_linux),
     "macos": as_object(not_linux),
     "pyodide": as_object(not_linux),
+    "android": as_object(not_linux),
     "ios": as_object(not_linux),
 }
 

bin/update_pythons.py

@@ -10,6 +10,7 @@
 from collections.abc import Mapping, MutableMapping
 from pathlib import Path
 from typing import Any, Final, Literal, TypedDict
+from xml.etree import ElementTree as ET
 
 import click
 import requests
@@ -20,6 +21,7 @@
 from rich.syntax import Syntax
 
 from cibuildwheel.extra import dump_python_configurations, get_pyodide_xbuildenv_info
+from cibuildwheel.platforms.android import android_triplet
 
 log = logging.getLogger("cibw")
 
@@ -57,14 +59,20 @@ class ConfigApple(TypedDict):
     url: str
 
 
+class ConfigAndroid(TypedDict):
+    identifier: str
+    version: str
+    url: str
+
+
 class ConfigPyodide(TypedDict):
     identifier: str
     version: str
     default_pyodide_version: str
     node_version: str
 
 
-AnyConfig = ConfigWinCP | ConfigWinPP | ConfigWinGP | ConfigApple | ConfigPyodide
+AnyConfig = ConfigWinCP | ConfigWinPP | ConfigWinGP | ConfigApple | ConfigAndroid | ConfigPyodide
 
 
 # The following set of "Versions" classes allow the initial call to the APIs to
@@ -320,6 +328,39 @@ def update_version_macos(
         return None
 
 
+class AndroidVersions:
+    # This should be replaced with official python.org downloads once they're available.
+    MAVEN_URL = "https://repo.maven.apache.org/maven2/com/chaquo/python/python"
+
+    def __init__(self) -> None:
+        response = requests.get(f"{self.MAVEN_URL}/maven-metadata.xml")
+        response.raise_for_status()
+        root = ET.fromstring(response.text)
+
+        self.versions: list[Version] = []
+        for version_elem in root.findall("./versioning/versions/version"):
+            version_str = version_elem.text
+            assert isinstance(version_str, str), version_str
+            self.versions.append(Version(version_str))
+
+    def update_version_android(
+        self, identifier: str, version: Version, spec: Specifier
+    ) -> ConfigAndroid | None:
+        sorted_versions = sorted(spec.filter(self.versions), reverse=True)
+
+        # Return a config using the highest version for the given specifier.
+        if sorted_versions:
+            max_version = sorted_versions[0]
+            triplet = android_triplet(identifier)
+            return ConfigAndroid(
+                identifier=identifier,
+                version=str(version),
+                url=f"{self.MAVEN_URL}/{max_version}/python-{max_version}-{triplet}.tar.gz",
+            )
+        else:
+            return None
+
+
 class CPythonIOSVersions:
     def __init__(self) -> None:
         response = requests.get(
@@ -413,6 +454,7 @@ def __init__(self) -> None:
         self.macos_pypy = PyPyVersions("64")
         self.macos_pypy_arm64 = PyPyVersions("ARM64")
 
+        self.android = AndroidVersions()
         self.ios_cpython = CPythonIOSVersions()
 
         self.graalpy = GraalPyVersions()
@@ -455,6 +497,8 @@ def update_config(self, config: MutableMapping[str, str]) -> None:
             config_update = self.windows_t_arm64.update_version_windows(spec)
         elif "win_arm64" in identifier and identifier.startswith("cp"):
             config_update = self.windows_arm64.update_version_windows(spec)
+        elif "android" in identifier:
+            config_update = self.android.update_version_android(identifier, version, spec)
         elif "ios" in identifier:
             config_update = self.ios_cpython.update_version_ios(identifier, version)
         elif "pyodide" in identifier:
@@ -490,17 +534,9 @@ def update_pythons(force: bool, level: str) -> None:
     with toml_file_path.open("rb") as f:
         configs = tomllib.load(f)
 
-    for config in configs["windows"]["python_configurations"]:
-        all_versions.update_config(config)
-
-    for config in configs["macos"]["python_configurations"]:
-        all_versions.update_config(config)
-
-    for config in configs["ios"]["python_configurations"]:
-        all_versions.update_config(config)
-
-    for config in configs["pyodide"]["python_configurations"]:
-        all_versions.update_config(config)
+    for platform in ["windows", "macos", "android", "ios", "pyodide"]:
+        for config in configs[platform]["python_configurations"]:
+            all_versions.update_config(config)
 
     result_toml = dump_python_configurations(configs)