fix: add Android support

docs/guide/crosscompile.md

@@ -52,7 +52,7 @@ correct suffix. These values are set by cibuildwheel when cross-compiling.
 
 It should be possible to cross-compile to Linux, but due to the challenges of
 getting the manylinux RHEL devtoolkit compilers, this is currently a TODO. See
-`py-build-cmake <https://tttapa.github.io/py-build-cmake/Cross-compilation.html>`\_
+[py-build-cmake](https://tttapa.github.io/py-build-cmake/Cross-compilation.html)
 for an alternative package's usage of toolchain files.
 
 ### Intel to Emscripten (Pyodide)
@@ -64,3 +64,24 @@ by setting `_PYTHON_SYSCONFIGDATA_NAME`. This causes values like `SOABI` and
 This is unfortunately incorrectly stripped from the cmake wrapper pyodide uses,
 so FindPython will report the wrong values, but pyodide-build will rename the
 .so's afterwards.
+
+## Android
+
+To build for Android, you'll need the following items, all of which will be
+provided automatically if you use cibuildwheel:
+
+- A Python environment in which `sys.platform`, `sysconfig`, etc. all simulate
+  Android.
+- A
+  [`CMAKE_TOOLCHAIN_FILE`](https://cmake.org/cmake/help/latest/envvar/CMAKE_TOOLCHAIN_FILE.html)
+  environment variable, pointing to a file which does at least the following:
+  - Set `CMAKE_SYSTEM_NAME`, `CMAKE_SYSTEM_PROCESSOR` and
+    `CMAKE_SYSTEM_VERSION`.
+  - Set `CMAKE_FIND_ROOT_PATH` to the location of the Python headers and
+    libraries.
+  - Set `CMAKE_CROSSCOMPILING_EMULATOR` to `/bin/sh -c [["$0" "$@"]]`. This
+    allows CMake to run Python in the simulated Android environment when policy
+    [CMP0190](https://cmake.org/cmake/help/latest/policy/CMP0190.html) is
+    active.
+- Compiler paths and flags, either in the toolchain file or in environment
+  variables.

docs/guide/faqs.md

@@ -42,7 +42,7 @@ is missing some value you need, please open an issue and let us know.
 
 ## Finding Python
 
-One common mistake when using FindPython is to forget to only request the
+When using `find_package(Python ...)`, you should only request the
 `Development.Module` component. If you request `Development`, you will also
 require the `Development.Embed` component, which will require the Python
 libraries to be found for linking. When building a module on Unix, you do not

tests/conftest.py

@@ -10,7 +10,7 @@
 import sysconfig
 from importlib import metadata
 from pathlib import Path
-from typing import Any, Literal, overload
+from typing import TYPE_CHECKING, Any, Literal, overload
 
 import virtualenv as _virtualenv
 
@@ -19,6 +19,8 @@
 else:
     import tomllib
 
+if TYPE_CHECKING:
+    from pytest_subprocess import FakeProcess
 
 import pytest
 from packaging.requirements import Requirement
@@ -30,6 +32,14 @@
 VIRTUALENV_VERSION = Version(metadata.version("virtualenv"))
 
 
+@pytest.fixture
+def fp(fp: FakeProcess) -> FakeProcess:
+    # For program_search._macos_binary_is_x86
+    fp.register(["lipo", fp.any()], returncode=1)
+    fp.register(["file", fp.any()], returncode=1)
+    return fp
+
+
 @pytest.fixture(scope="session")
 def pep518_wheelhouse(tmp_path_factory: pytest.TempPathFactory) -> Path:
     wheelhouse = tmp_path_factory.mktemp("wheelhouse")