import os import platform import re import sys import typing from collections.abc import Callable from dataclasses import dataclass from pathlib import Path from shutil import rmtree, which from subprocess import CalledProcessError from textwrap import dedent from zipfile import ZipFile import pytest from .test_projects import new_c_project, new_meson_project from .utils import cibuildwheel_run, expected_wheels pytestmark = pytest.mark.android CIBW_PLATFORM = os.environ.get("CIBW_PLATFORM", "android") if CIBW_PLATFORM != "android": pytest.skip(f"{CIBW_PLATFORM=}", allow_module_level=True) if (platform.system(), platform.machine()) not in [ ("Linux", "x86_64"), ("Darwin", "arm64"), ("Darwin", "x86_64"), ]: pytest.skip( f"cibuildwheel does not support building Android wheels on " f"{platform.system()} {platform.machine()}", allow_module_level=True, ) # Azure Pipelines does not set the CI variable. ci = any(key in os.environ for key in ["CI", "TF_BUILD"]) if "ANDROID_HOME" not in os.environ: msg = "ANDROID_HOME environment variable is not set" # Fail if we're on a CI service which is supposed to have the Android SDK # pre-installed; otherwise skip the module. if "GITHUB_ACTIONS" in os.environ or "TF_BUILD" in os.environ: pytest.fail(msg) else: pytest.skip(msg, allow_module_level=True) # Many CI services don't support running the Android emulator: see platforms.md. supports_emulator = (not ci) or ("GITHUB_ACTIONS" in os.environ and platform.system() == "Linux") T = typing.TypeVar("T", bound=Callable[..., typing.Any]) def needs_emulator(test: T) -> T: # All copies of the testbed app run on the same emulator with the same # application ID, so these tests must be run serially. test = pytest.mark.serial(test) if not supports_emulator: test = pytest.mark.skip("This CI platform doesn't support the emulator")(test) return test @dataclass class Architecture: linux_machine: str macos_machine: str android_abi: str archs = [ Architecture("aarch64", "arm64", "arm64_v8a"), Architecture("x86_64", "x86_64", "x86_64"), ] native_arch = next( arch for arch in archs if platform.machine() in [arch.linux_machine, arch.macos_machine] ) cp313_env = { "CIBW_PLATFORM": "android", "CIBW_BUILD": "cp313-*", } def test_android_home(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project().generate(tmp_path) env = os.environ.copy() del env["ANDROID_HOME"] with pytest.raises(CalledProcessError): cibuildwheel_run(tmp_path, env={**env, **cp313_env}) assert "ANDROID_HOME environment variable is not set" in capfd.readouterr().err # android-env.sh may need to install the NDK, and it isn't safe to do that multiple # times in parallel. So make sure there's at least one test which gets as far as doing # a build, which is marked as serial so it will run before the parallel tests, but isn't # marked as needs_emulator so it will run on all CI platforms. @pytest.mark.serial def test_expected_wheels(tmp_path: Path, spam_env: dict[str, str]) -> None: # Since this test covers all Python versions, check the cross venv. test_module = "_cross_venv_test_android" project = new_c_project(setup_py_add=f"import {test_module}") project.files[f"{test_module}.py"] = (Path(__file__).parent / f"{test_module}.py").read_text() project.generate(tmp_path) # Build wheels for all Python versions on the current architecture. del spam_env["CIBW_BUILD"] if not supports_emulator: del spam_env["CIBW_TEST_COMMAND"] wheels = cibuildwheel_run(tmp_path, add_env=spam_env) assert wheels == expected_wheels( "spam", "0.1.0", platform="android", machine_arch=native_arch.android_abi ) @needs_emulator def test_frontend_good(tmp_path: Path, build_frontend_env: dict[str, str]) -> None: new_c_project().generate(tmp_path) wheels = cibuildwheel_run( tmp_path, add_env={**cp313_env, **build_frontend_env, "CIBW_TEST_COMMAND": "python -m site"}, ) assert wheels == [f"spam-0.1.0-cp313-cp313-android_24_{native_arch.android_abi}.whl"] @pytest.mark.parametrize("frontend", ["pip"]) def test_frontend_bad(frontend: str, tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project().generate(tmp_path) with pytest.raises(CalledProcessError): cibuildwheel_run( tmp_path, add_env={**cp313_env, "CIBW_BUILD_FRONTEND": frontend}, ) assert ( f"Android requires the build frontend to be 'build' or 'uv', not '{frontend}'" in capfd.readouterr().err ) @needs_emulator def test_archs(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project().generate(tmp_path) # Build all architectures while checking the handling of the `before` commands. command_pattern = 'echo "Hello from {0}, package={{package}}, python=$(which python)"' output_pattern = ( f"Hello from {{0}}, package={tmp_path}, python=/.+/cp313-android_{{1}}/venv/bin/python" ) wheels = cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_ARCHS": "all", "CIBW_BEFORE_ALL": "echo 'Hello from before_all'", "CIBW_BEFORE_BUILD": command_pattern.format("before_build"), "CIBW_BEFORE_TEST": command_pattern.format("before_test"), "CIBW_TEST_COMMAND": ( "python -c 'import platform; print(f\"Hello from {platform.machine()}\")'" ), }, ) assert wheels == [f"spam-0.1.0-cp313-cp313-android_24_{arch.android_abi}.whl" for arch in archs] stdout, stderr = capfd.readouterr() lines = (line for line in stdout.splitlines() if line.startswith("Hello from")) assert next(lines) == "Hello from before_all" # All architectures should be built, but only the native architecture should run tests. for arch in archs: abi = arch.android_abi assert re.fullmatch(output_pattern.format("before_build", abi), next(lines)) if arch == native_arch: assert re.fullmatch(output_pattern.format("before_test", abi), next(lines)) assert next(lines) == f"Hello from {arch.linux_machine}" else: assert ( f"Skipping tests for {arch.android_abi}, as the build machine " f"only supports {native_arch.android_abi}" ) in stderr try: line = next(lines) except StopIteration: pass else: pytest.fail(f"Unexpected line: {line!r}") def test_build_requires(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: # Build-time requirements should be installed for the build platform, not for Android. Prove # this by installing some non-pure-Python requirements and using them in setup.py. # # setup_requires is installed via ProjectBuilder.get_requires_for_build. project = new_c_project( setup_py_setup_args_add="setup_requires=['cmake==3.31.4']", setup_py_add=dedent( """\ if "egg_info" not in sys.argv: import subprocess subprocess.run(["cmake", "--version"], check=True) from bitarray import bitarray print(f"{bitarray('10110').count()=}") """ ), ) # [build_system] requires is installed via ProjectBuilder.build_system_requires. project.files["pyproject.toml"] = dedent( """\ [build-system] requires = ["setuptools", "wheel", "bitarray==3.3.2"] """ ) project.generate(tmp_path) cibuildwheel_run(tmp_path, add_env={**cp313_env}) # Test for a specific version to minimize the chance that we ran a system cmake. stdout = capfd.readouterr().out assert "cmake version 3.31.4" in stdout assert "bitarray('10110').count()=3" in stdout @pytest.fixture def spam_env(tmp_path: Path) -> dict[str, str]: project = new_c_project() project.files["test_spam.py"] = dedent( """\ import spam def test_spam() -> None: assert spam.filter("ham") assert not spam.filter("spam") print("Spam test passed") """ ) project.files["test_empty.py"] = dedent( """\ def test_empty() -> None: pass """ ) project.generate(tmp_path) return { **cp313_env, "CIBW_TEST_SOURCES": "test_spam.py test_empty.py", "CIBW_TEST_REQUIRES": "pytest==8.3.5", "CIBW_TEST_COMMAND": "python -m pytest", } @needs_emulator @pytest.mark.parametrize( ("command", "expected_output"), [ ("python3 -c 'import test_spam; test_spam.test_spam()'", "Spam test passed"), ("python -m pytest", "=== 2 passed in "), ("python -m pytest test_spam.py", "=== 1 passed in "), ("pytest test_spam.py", "=== 1 passed in "), ], ) def test_test_command_good( command: str, expected_output: str, tmp_path: Path, spam_env: dict[str, str], capfd: pytest.CaptureFixture[str], ) -> None: cibuildwheel_run(tmp_path, add_env={**spam_env, "CIBW_TEST_COMMAND": command}) stdout, stderr = capfd.readouterr() assert expected_output in stdout if not command.startswith("python"): assert ( f"Test command {command!r} is not supported on Android. cibuildwheel " "will try to execute it as if it started with 'python -m'." ) in stderr BAD_FORMAT_ERROR = ( "Test command '{}' is not supported on Android. " "Command must begin with 'python' or 'python3', and contain '-m' or '-c'." ) BAD_PLACEHOLDER_ERROR = ( "Test command '{}' with a '{{project}}' or '{{package}}' placeholder " "is not supported on Android" ) @needs_emulator @pytest.mark.parametrize( ("command", "expected_output"), [ # Build-time failure ("./test_spam.py", BAD_FORMAT_ERROR.format("./test_spam.py")), ("python test_spam.py", BAD_FORMAT_ERROR.format("python test_spam.py")), ("pytest {project}", BAD_PLACEHOLDER_ERROR.format("pytest {project}")), ("pytest {package}", BAD_PLACEHOLDER_ERROR.format("pytest {package}")), # Runtime failure ("pytest test_ham.py", "not found: test_ham.py"), ], ) def test_test_command_bad( command: str, expected_output: str, tmp_path: Path, spam_env: dict[str, str], capfd: pytest.CaptureFixture[str], ) -> None: with pytest.raises(CalledProcessError): cibuildwheel_run(tmp_path, add_env={**spam_env, "CIBW_TEST_COMMAND": command}) assert expected_output in capfd.readouterr().err @needs_emulator @pytest.mark.parametrize( ("options", "expected"), [ ("", 0), ("-E", 1), ], ) def test_test_command_python_options( options: str, expected: int, tmp_path: Path, capfd: pytest.CaptureFixture[str] ) -> None: project = new_c_project() project.generate(tmp_path) command = 'import sys; print(f"{sys.flags.ignore_environment=}")' cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_TEST_COMMAND": f"python {options} -c '{command}'", }, ) assert f"sys.flags.ignore_environment={expected}" in capfd.readouterr().out @needs_emulator def test_package_subdir( tmp_path: Path, spam_env: dict[str, str], capfd: pytest.CaptureFixture[str] ) -> None: spam_paths = list(tmp_path.iterdir()) package_dir = tmp_path / "package" package_dir.mkdir() for path in spam_paths: path.rename(package_dir / path.name) spam_env["CIBW_TEST_SOURCES"] = " ".join( f"package/{path}" for path in spam_env["CIBW_TEST_SOURCES"].split() ) cibuildwheel_run(tmp_path, package_dir, add_env=spam_env) assert "=== 2 passed in " in capfd.readouterr().out @needs_emulator def test_no_test_sources(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project().generate(tmp_path) with pytest.raises(CalledProcessError): cibuildwheel_run( tmp_path, add_env={**cp313_env, "CIBW_TEST_COMMAND": "python -m unittest discover"}, ) assert ( "On this platform, you must copy your test files to the testbed app by " "setting the `test-sources` option" ) in capfd.readouterr().err @needs_emulator def test_environment_markers(tmp_path: Path) -> None: project = new_c_project() test_filename = "test_environment_markers.py" project.files[test_filename] = dedent( """\ import pytest def test_android() -> None: import certifi def test_not_android() -> None: try: import platformdirs except ImportError: pass else: pytest.fail("`platformdirs` should not have been installed") """ ) project.generate(tmp_path) cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_TEST_COMMAND": f"python -m pytest {test_filename}", "CIBW_TEST_SOURCES": test_filename, "CIBW_TEST_REQUIRES": "pytest certifi;sys_platform=='android' platformdirs;sys_platform!='android'", }, ) @needs_emulator def test_verbosity(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project().generate(tmp_path) test_env = { **cp313_env, "CIBW_TEST_COMMAND": """python -c 'print("Hello world")'""", } verbose_lines = [ "> Task :app:packageDebug", # Gradle "I/TestRunner: run started: 1 tests", # Logcat ] cibuildwheel_run(tmp_path, add_env=test_env) stdout = capfd.readouterr().out for line in verbose_lines: assert line not in stdout cibuildwheel_run( tmp_path, add_env={**test_env, "CIBW_BUILD_VERBOSITY": "1"}, ) stdout = capfd.readouterr().out for line in verbose_lines: assert line in stdout @needs_emulator def test_api_level(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: project = new_c_project( # Check that the the compiler options are set correctly. spam_c_top_level_add=dedent( """\ #if __ANDROID_API__ != 33 #error Unexpected API level; the following syntax error will show the actual value: __ANDROID_API__ #endif """ ) ) project.files["pyproject.toml"] = dedent( """\ [build-system] requires = ["setuptools"] [tool.cibuildwheel] # Test setting API level in pyproject.toml (test_libcxx covers setting # it in the outer environment.) android.environment.ANDROID_API_LEVEL = "33" android.environment.PIP_EXTRA_INDEX_URL = "https://chaquo.com/pypi-13.1" """ ) project.generate(tmp_path) wheels = cibuildwheel_run( tmp_path, add_env={ **cp313_env, # Verify that Android dependencies can be installed from the Chaquopy repository, and # that wheels tagged with an older version of Android (in this case 24) are still # accepted. "CIBW_TEST_REQUIRES": "bitarray==3.0.0", "CIBW_TEST_COMMAND": ( "python -c 'from bitarray import bitarray; print(~bitarray(\"01100\"))'" ), }, ) assert wheels == [f"spam-0.1.0-cp313-cp313-android_33_{native_arch.android_abi}.whl"] assert "bitarray('10011')" in capfd.readouterr().out @needs_emulator def test_libcxx(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: project_dir = tmp_path / "project" output_dir = tmp_path / "output" # cibuildwheel should be able to run `patchelf` and `wheel` even when its # environment's `bin` directory is not on the PATH. non_venv_path = ":".join( item for item in os.environ["PATH"].split(":") if Path(item) != Path(sys.executable).parent ) # A C++ package should include libc++, and the extension module should be able to # find it using DT_RUNPATH. new_c_project(setup_py_extension_args_add="language='c++'").generate(project_dir) script = 'import spam; print(", ".join(f"{s}: {spam.filter(s)}" for s in ["ham", "spam"]))' cp313_test_env = { **cp313_env, "CIBW_TEST_COMMAND": f"python -c '{script}'", "PATH": non_venv_path, } # Including external libraries requires API level 24. This is enforced by auditwheel. cp313_android_21_env = { **cp313_test_env, # Test setting API level in the outer environment (test_api_level covers setting # it in pyproject.toml.) "ANDROID_API_LEVEL": "21", } with pytest.raises(CalledProcessError): cibuildwheel_run(project_dir, add_env=cp313_android_21_env, output_dir=output_dir) assert ( "Grafting libraries with RUNPATH requires API level 24 or higher" in capfd.readouterr().err ) wheels = cibuildwheel_run(project_dir, add_env=cp313_test_env, output_dir=output_dir) assert wheels == [f"spam-0.1.0-cp313-cp313-android_24_{native_arch.android_abi}.whl"] names = ZipFile(output_dir / wheels[0]).namelist() libcxx_names = [ name for name in names if re.fullmatch(r"spam\.libs/libc\+\+_shared-[0-9a-f]{8}\.so", name) ] assert len(libcxx_names) == 1 assert "ham: 1, spam: 0" in capfd.readouterr().out # A C package should not include libc++, and can therefore use an older API level. rmtree(project_dir) rmtree(output_dir) new_c_project().generate(project_dir) wheels = cibuildwheel_run(project_dir, add_env=cp313_android_21_env, output_dir=output_dir) assert wheels == [f"spam-0.1.0-cp313-cp313-android_21_{native_arch.android_abi}.whl"] for name in ZipFile(output_dir / wheels[0]).namelist(): assert ".libs" not in name @needs_emulator def test_repair_none(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: new_c_project(setup_py_extension_args_add="language='c++'").generate(tmp_path) with pytest.raises(CalledProcessError): cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_REPAIR_WHEEL_COMMAND": "", "CIBW_TEST_COMMAND": "python -c 'import spam'", }, ) assert 'dlopen failed: library "libc++_shared.so" not found' in capfd.readouterr().err def test_repair_ldpaths(tmp_path: Path) -> None: new_c_project().generate(tmp_path) repair_path = tmp_path / "repair.py" repair_path.write_text( dedent( """\ #!/usr/bin/env python import shutil import sys from pathlib import Path assert len(sys.argv) == 4, sys.argv ldpaths = list(map(Path, sys.argv[1].split(":"))) dest_dir = sys.argv[2] wheel = sys.argv[3] for name in ["libc++_shared.so", "libomp.so"]: assert any((lp / name).exists() for lp in ldpaths), (name, ldpaths) shutil.copy(wheel, dest_dir) """ ) ) repair_path.chmod(0o755) wheels = cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_REPAIR_WHEEL_COMMAND": f"{repair_path} {{ldpaths}} {{dest_dir}} {{wheel}}", }, ) assert wheels == [f"spam-0.1.0-cp313-cp313-android_24_{native_arch.android_abi}.whl"] @pytest.mark.parametrize( ("script", "error"), [ ("", "did not produce a wheel"), ("touch $dest_dir/one.whl $dest_dir/two.whl", "produced multiple wheels"), ("touch $dest_dir/one-0.0.1-py3-none-any.whl", "pure Python wheel was generated"), ], ) def test_repair_error( script: str, error: str, tmp_path: Path, capfd: pytest.CaptureFixture[str] ) -> None: new_c_project().generate(tmp_path) repair_path = tmp_path / "repair.sh" repair_path.write_text( dedent( f"""\ #!/bin/sh dest_dir=$1 {script} """ ) ) repair_path.chmod(0o755) with pytest.raises(CalledProcessError): cibuildwheel_run( tmp_path, add_env={**cp313_env, "CIBW_REPAIR_WHEEL_COMMAND": f"{repair_path} {{dest_dir}}"}, ) assert error in capfd.readouterr().err # This also tests integration with pkgconf, because Meson uses it to find Python. @needs_emulator def test_meson(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: # Alter spam.filter to return the value of a Fortran function. new_meson_project( spam_c_top_level_add="int fortran_func_();", spam_c_function_add="sts = fortran_func_();", project_args_add="'fortran',", extension_args_add="'fortran.f90', link_language: 'fortran',", ).generate(tmp_path) # TODO: remove once meson-python has a release with Android support. pyproject_path = tmp_path / "pyproject.toml" pyproject_path.write_text( pyproject_path.read_text().replace( "meson-python", "meson-python @ git+https://github.com/mesonbuild/meson-python@main" ) ) # Add Fortran code. (tmp_path / "fortran.f90").write_text( dedent( """\ integer*4 function fortran_func() fortran_func = 42 end """ ) ) script = 'import spam; print(f"result: {spam.filter("")}")' cibuildwheel_run( tmp_path, add_env={**cp313_env, "CIBW_TEST_COMMAND": f"python -c '{script}'"}, ) assert "result: 42" in capfd.readouterr().out @needs_emulator def test_xbuild_files(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: # Verify that we've replaced the correct files by compiling against a non-trivial # function from libnpymath.a. new_c_project( setup_py_add=dedent( """\ import numpy as np np_include = np.get_include() np_lib = f"{np_include}/../lib" libraries.append("npymath") """ ), setup_py_extension_args_add="include_dirs=[np_include], library_dirs=[np_lib]", spam_c_top_level_add="#include ", spam_c_function_add="sts = npy_float_to_half(42);", ).generate(tmp_path) (tmp_path / "pyproject.toml").write_text( dedent( """\ [build-system] requires = ["setuptools", "numpy==2.3.2"] """ ) ) script = 'import spam; print(f"result: {spam.filter(""):#x}")' cibuildwheel_run( tmp_path, add_env={ **cp313_env, # TODO: remove this once there are official Android NumPy wheels on PyPI. "PIP_EXTRA_INDEX_URL": "https://chaquo.com/pypi-test", "CIBW_ARCHS": "all", # Include both native and non-native archs. "CIBW_TEST_COMMAND": f"python -c '{script}'", }, ) assert "result: 0x5140" in capfd.readouterr().out @needs_emulator def test_setuptools_rust(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: """ Test Android cross-compilation using the setuptools-rust toolchain. """ if not which("rustup") or not which("cargo"): pytest.skip("rustup and cargo are required for this test") # Initialize a basic project and override files for setuptools-rust project = new_c_project() project.files["pyproject.toml"] = dedent( """\ [build-system] requires = ["setuptools", "wheel", "setuptools-rust"] """ ) project.files["setup.py"] = dedent( """\ from setuptools import setup from setuptools_rust import Binding, RustExtension setup( name="spam", version="0.1.0", rust_extensions=[RustExtension("spam.rust_ext", binding=Binding.PyO3)], zip_safe=False, ) """ ) project.files["Cargo.toml"] = dedent( """\ [package] name = "rust_ext" version = "0.1.0" edition = "2021" [lib] name = "rust_ext" crate-type = ["cdylib"] [dependencies] pyo3 = { version = "0.23.3", features = ["extension-module"] } """ ) # Create the Rust source directory and file (tmp_path / "src").mkdir() project.files["src/lib.rs"] = dedent( """\ use pyo3::prelude::*; #[pyfunction] fn hello() -> PyResult { Ok("Hello from Rust via setuptools-rust!".to_string()) } #[pymodule] fn rust_ext(_py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> { m.add_function(wrap_pyfunction!(hello, m)?)?; Ok(()) } """ ) project.generate(tmp_path) # Command to verify the built extension on the Android emulator test_command = "python -c 'import spam.rust_ext; print(spam.rust_ext.hello())'" # Run cibuildwheel to build and test the wheel wheels = cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_TEST_COMMAND": test_command, "CIBW_BUILD_VERBOSITY": "1", }, ) # Verification assert len(wheels) == 1 stdout = capfd.readouterr().out assert "Hello from Rust via setuptools-rust!" in stdout @needs_emulator def test_maturin(tmp_path: Path, capfd: pytest.CaptureFixture[str]) -> None: """ Test Android cross-compilation using the maturin backend. """ if not which("rustup") or not which("cargo"): pytest.skip("rustup and cargo are required for this test") project = new_c_project() project.files["pyproject.toml"] = dedent( """\ [build-system] # maturin >= 1.11.0 is required for reliable Android cross-compilation support. requires = ["maturin>=1.11.0,<2.0"] build-backend = "maturin" [project] name = "spam" version = "0.1.0" """ ) project.files["Cargo.toml"] = dedent( """\ [package] name = "spam" version = "0.1.0" edition = "2021" [lib] name = "spam" crate-type = ["cdylib"] [dependencies] pyo3 = { version = "0.23.3", features = ["extension-module"] } """ ) (tmp_path / "src").mkdir() project.files["src/lib.rs"] = dedent( """\ use pyo3::prelude::*; #[pyfunction] fn hello() -> PyResult { Ok("Hello from Rust via maturin!".to_string()) } #[pymodule] fn spam(_py: Python, m: &Bound<'_, PyModule>) -> PyResult<()> { m.add_function(wrap_pyfunction!(hello, m)?)?; Ok(()) } """ ) project.generate(tmp_path) (tmp_path / "setup.py").unlink() test_command = "python -c 'import spam; print(spam.hello())'" wheels = cibuildwheel_run( tmp_path, add_env={ **cp313_env, "CIBW_TEST_COMMAND": test_command, "CIBW_BUILD_VERBOSITY": "1", }, ) assert len(wheels) == 1 stdout = capfd.readouterr().out assert "Hello from Rust via maturin!" in stdout