feat: add support for building Android wheels (#2349)

* Add Android to resource files

* Add Android to miscellaneous places

* Add Android documentation

* Docs cleanups

* Add Android platform module; implement top-level structure and target Python installation

* Implement setup_env and build_wheel

* lru-dict build working

* Alter prefix in sysconfigdata file; fix various issues with FLAGS variables

* Implement Android testing

* Add type annotations to _cross_venv

* Revert Python 3.8 to pip 25.0.1

* Make test-sources required on Android

* Add Android integration tests

* Test cleanups

* Add test of all available Python versions

* Update test-sources and test-command behavior to match iOS

* Documentation cleanups

* Replace Builder class with a set of global functions

* Rename "env" to "build_env"

* Remove Chaquopy repository from default pip command line

* Move native_platform to platforms module

* Fix parse_config_settings

Co-authored-by: Joe Rickerby <joerick@mac.com>

* Add unit tests for parse_config_settings and arch_synonym

* Make `shell_prepared` arguments keyword-only, and add tests for the commands that use it

* Replace `importlib.util.spec_from_file_location` with `runpy.run_path`

* Use python-build-standalone

* Update Android Python

* Enable KVM in Linux CI

* Move KVM code to test_android.py

* Use Java 17 on Azure

* Install emulator if necessary before running -accel-check

* Free up additional disk space on Linux runners

* Add sudo

* Skip emulator tests on CI platforms that don't support it

* Download Android Python from Maven Central

* Free up more disk space on Linux runners

* fix: minor fixups

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

* Set sysconfig._BASE_PREFIX to support sysconfig.get_path("include")

* Get ANDROID_API_LEVEL from the build environment, not cibuildwheel's own environment

* Correct relative path of test-sources

* Pass a CMake toolchain file to the build

* Add "repair" step which adds libc++ to the wheel when necessary

* Add missing needs_emulator decorator

* Provide useful error message if ANDROID_HOME is not set

* Remove use of HOST environment variable

* Update to Python 3.15.5

* Fix PyLint warnings, clarify comment

* Group common arguments into a dataclass

* Handle environment variables containing newlines

* Discourage the use of `pytest` test commands without `python -m`

* Use single quotes in user-visible messages

* Improve testing documentation

* Pass wheel filename to `log.build_end`

* In GitHub Actions example, skip Android tests on macOS

* Correct relative paths in `patchelf --set-rpath`

* Clarify `test-sources` docs

* Update to Python 3.13.5+20250722.214220

---------

Signed-off-by: Henry Schreiner <henryschreineriii@gmail.com>
Co-authored-by: Joe Rickerby <joerick@mac.com>
Co-authored-by: Henry Schreiner <henryschreineriii@gmail.com>

cibuildwheel/architecture.py

@@ -17,16 +17,25 @@ PRETTY_NAMES: Final[dict[PlatformName, str]] = {
     "macos": "macOS",
     "windows": "Windows",
     "pyodide": "Pyodide",
+    "android": "Android",
     "ios": "iOS",
 }
 
 ARCH_SYNONYMS: Final[list[dict[PlatformName, str | None]]] = [
-    {"linux": "x86_64", "macos": "x86_64", "windows": "AMD64"},
+    {"linux": "x86_64", "macos": "x86_64", "windows": "AMD64", "android": "x86_64"},
     {"linux": "i686", "macos": None, "windows": "x86"},
-    {"linux": "aarch64", "macos": "arm64", "windows": "ARM64"},
+    {"linux": "aarch64", "macos": "arm64", "windows": "ARM64", "android": "arm64_v8a"},
 ]
 
 
+def arch_synonym(arch: str, from_platform: PlatformName, to_platform: PlatformName) -> str | None:
+    for arch_synonym_ in ARCH_SYNONYMS:
+        if arch == arch_synonym_.get(from_platform):
+            return arch_synonym_.get(to_platform, arch)
+
+    return arch
+
+
 def _check_aarch32_el0() -> bool:
     """Check if running armv7l natively on aarch64 is supported"""
     if not sys.platform.startswith("linux"):
@@ -42,7 +51,7 @@ def _check_aarch32_el0() -> bool:
 
 @typing.final
 class Architecture(StrEnum):
-    # mac/linux archs
+    # mac/linux/android archs
     x86_64 = auto()
 
     # linux archs
@@ -65,6 +74,9 @@ class Architecture(StrEnum):
     # WebAssembly
     wasm32 = auto()
 
+    # android archs
+    arm64_v8a = auto()
+
     # iOS "multiarch" architectures that include both
     # the CPU architecture and the ABI.
     arm64_iphoneos = auto()
@@ -123,15 +135,12 @@ class Architecture(StrEnum):
         # we might need to rename the native arch to the machine we're running
         # on, as the same arch can have different names on different platforms
         if host_platform != platform:
-            for arch_synonym in ARCH_SYNONYMS:
-                if native_machine == arch_synonym.get(host_platform):
-                    synonym = arch_synonym[platform]
+            synonym = arch_synonym(native_machine, host_platform, platform)
+            if synonym is None:
+                # can't build anything on this platform
+                return None
 
-                    if synonym is None:
-                        # can't build anything on this platform
-                        return None
-
-                    native_architecture = Architecture(synonym)
+            native_architecture = Architecture(synonym)
 
         return native_architecture
 
@@ -166,6 +175,7 @@ class Architecture(StrEnum):
             "macos": {Architecture.x86_64, Architecture.arm64, Architecture.universal2},
             "windows": {Architecture.x86, Architecture.AMD64, Architecture.ARM64},
             "pyodide": {Architecture.wasm32},
+            "android": {Architecture.x86_64, Architecture.arm64_v8a},
             "ios": {
                 Architecture.x86_64_iphonesimulator,
                 Architecture.arm64_iphonesimulator,