Allow overriding the list of avoided build requirements

CHANGELOG.md

@@ -9,8 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
-- `pyodide config` exposes new variables: `pyodide_root`, `pyodide_abi_version`, and `python_include_dir`
-  [#186](https://github.com/pyodide/pyodide-build/pull/186)
+- `pyodide config` exposes new variables: `pyodide_root`, `pyodide_abi_version`, and `python_include_dir`,
+  and `ignored_build_requirements`.
+  [#186](https://github.com/pyodide/pyodide-build/pull/186) and [#187](https://github.com/pyodide/pyodide-build/pull/187)
 
 ## [0.30.0] - 2025/04/08
 

pyodide_build/build_env.py

@@ -15,7 +15,6 @@
 
 from pyodide_build import __version__
 from pyodide_build.common import default_xbuildenv_path, search_pyproject_toml, to_bool
-from pyodide_build.config import ConfigManager, CrossBuildEnvConfigManager
 
 RUST_BUILD_PRELUDE = """
 rustup default ${RUST_TOOLCHAIN}
@@ -123,11 +122,20 @@ def in_xbuildenv() -> bool:
     return pyodide_root.name == "pyodide-root"
 
 
+def _load_config_manager():
+    """Lazily load ConfigManager so that we can avoid circular imports."""
+    from pyodide_build.config import ConfigManager, CrossBuildEnvConfigManager
+
+    return ConfigManager, CrossBuildEnvConfigManager
+
+
 @functools.cache
 def get_build_environment_vars(pyodide_root: Path) -> dict[str, str]:
     """
     Get common environment variables for the in-tree and out-of-tree build.
     """
+    _, CrossBuildEnvConfigManager = _load_config_manager()
+
     config_manager = CrossBuildEnvConfigManager(pyodide_root)
     env = config_manager.to_env()
 
@@ -147,6 +155,7 @@ def get_build_environment_vars(pyodide_root: Path) -> dict[str, str]:
 
 @functools.cache
 def get_host_build_environment_vars() -> dict[str, str]:
+    ConfigManager, _ = _load_config_manager()
     manager = ConfigManager()
     return manager.to_env()
 

pyodide_build/cli/config.py

@@ -32,7 +32,7 @@ def list_config():
     configs = _get_configs()
 
     for k, v in configs.items():
-        typer.echo(f"{k}={v}")
+        typer.echo(f'{k}="{v}"')
 
 
 @app.command("get")

pyodide_build/config.py

@@ -10,6 +10,7 @@
     exit_with_stdio,
     search_pyproject_toml,
 )
+from pyodide_build.constants import BASE_IGNORED_REQUIREMENTS
 from pyodide_build.logger import logger
 
 
@@ -199,6 +200,7 @@ def _get_make_environment_vars(self) -> Mapping[str, str]:
     "build_dependency_index_url": "BUILD_DEPENDENCY_INDEX_URL",
     "default_cross_build_env_url": "DEFAULT_CROSS_BUILD_ENV_URL",
     "xbuildenv_path": "PYODIDE_XBUILDENV_PATH",
+    "ignored_build_requirements": "IGNORED_BUILD_REQUIREMENTS",
     # maintainer only
     "_f2c_fixes_wrapper": "_F2C_FIXES_WRAPPER",
 }
@@ -218,6 +220,7 @@ def _get_make_environment_vars(self) -> Mapping[str, str]:
     "build_dependency_index_url",
     "default_cross_build_env_url",
     "xbuildenv_path",
+    "ignored_build_requirements",
     # maintainer only
     "_f2c_fixes_wrapper",
 }
@@ -240,6 +243,8 @@ def _get_make_environment_vars(self) -> Mapping[str, str]:
     "build_dependency_index_url": "https://pypi.anaconda.org/pyodide/simple",
     "default_cross_build_env_url": "",
     "xbuildenv_path": "",
+    # A list of PEP508 build-time requirements to be ignored when building a wheel
+    "ignored_build_requirements": " ".join(BASE_IGNORED_REQUIREMENTS),
     # maintainer only
     "_f2c_fixes_wrapper": "",
 }
@@ -279,4 +284,5 @@ def _get_make_environment_vars(self) -> Mapping[str, str]:
     "pyodide_abi_version": "PYODIDE_ABI_VERSION",
     "pyodide_root": "PYODIDE_ROOT",
     "python_include_dir": "PYTHONINCLUDE",
+    "ignored_build_requirements": "IGNORED_BUILD_REQUIREMENTS",
 }

pyodide_build/constants.py

@@ -0,0 +1,8 @@
+# Some reusable constants that are used at various sources in our code.
+# TODO: collect and add more constants here.
+
+BASE_IGNORED_REQUIREMENTS: list[str] = [
+    # mesonpy installs patchelf in linux platform but we don't want it.
+    "patchelf",
+    "oldest-supported-numpy",
+]

pyodide_build/pypabuild.py

@@ -17,6 +17,7 @@
 from pyodide_build import _f2c_fixes, common, pywasmcross, uv_helper
 from pyodide_build.build_env import (
     get_build_flag,
+    get_host_build_flag,
     get_hostsitepackages,
     get_pyversion,
     get_unisolated_packages,
@@ -31,12 +32,6 @@
     _ProjectBuilder,
 )
 
-AVOIDED_REQUIREMENTS = [
-    # mesonpy installs patchelf in linux platform but we don't want it.
-    "patchelf",
-    "oldest-supported-numpy",
-]
-
 # corresponding env variables for symlinks
 SYMLINK_ENV_VARS = {
     "cc": "CC",
@@ -97,6 +92,8 @@ def _runner(cmd, cwd=None, extra_environ=None):
 
 
 def symlink_unisolated_packages(env: DefaultIsolatedEnv) -> None:
+    from pyodide_build.build_env import get_build_flag, get_unisolated_packages
+
     pyversion = get_pyversion()
     site_packages_path = f"lib/{pyversion}/site-packages"
     env_site_packages = Path(env.path) / site_packages_path
@@ -131,14 +128,17 @@ def remove_avoided_requirements(
 def install_reqs(
     build_env: Mapping[str, str], env: DefaultIsolatedEnv, reqs: set[str]
 ) -> None:
+    IGNORED_BUILD_REQUIREMENTS = [
+        pkg.strip() for pkg in get_host_build_flag("IGNORED_BUILD_REQUIREMENTS").split()
+    ]
     # propagate PIP config from build_env to current environment
     with common.replace_env(
         os.environ | {k: v for k, v in build_env.items() if k.startswith("PIP")}
     ):
         env.install(
             remove_avoided_requirements(
                 reqs,
-                get_unisolated_packages() + AVOIDED_REQUIREMENTS,
+                get_unisolated_packages() + IGNORED_BUILD_REQUIREMENTS,
             )
         )
 
@@ -256,7 +256,6 @@ def make_command_wrapper_symlinks(symlink_dir: Path) -> dict[str, str]:
     -------
     The dictionary of compiler environment variables that points to the symlinks.
     """
-
     # For maintainers:
     # - you can set "_f2c_fixes_wrapper" variable in pyproject.toml
     # in order to change the script to use when cross-compiling
@@ -315,6 +314,7 @@ def get_build_env(
     Returns a dict of environment variables that should be used when building
     a package with pypa/build.
     """
+    from pyodide_build.build_env import get_build_flag
 
     kwargs = {
         "pkgname": pkgname,

pyodide_build/tests/test_config.py

@@ -42,6 +42,7 @@ def test_load_config_from_file(self, tmp_path, reset_env_vars, reset_cache):
                                   default_cross_build_env_url = "https://example.com/cross_build_env.tar.gz"
                                   skip_emscripten_version_check = "1"
                                   xbuildenv_path = "my_custom/xbuildenv_path"
+                                  ignored_build_requirements = "cmake foo bar"
                                   """)
 
         config_manager = ConfigManager()
@@ -54,6 +55,7 @@ def test_load_config_from_file(self, tmp_path, reset_env_vars, reset_cache):
         )
         assert config["skip_emscripten_version_check"] == "1"
         assert config["xbuildenv_path"] == "my_custom/xbuildenv_path"
+        assert config["ignored_build_requirements"] == "cmake foo bar"
 
 
 class TestCrossBuildEnvConfigManager_OutOfTree:
@@ -126,12 +128,14 @@ def test_load_config_from_env(self, dummy_xbuildenv, reset_env_vars, reset_cache
             "CMAKE_TOOLCHAIN_FILE": "/path/to/toolchain",
             "MESON_CROSS_FILE": "/path/to/crossfile",
             "PYODIDE_XBUILDENV_PATH": "/path/to/xbuildenv",
+            "IGNORED_BUILD_REQUIREMENTS": "cmake foo bar",
         }
 
         config = config_manager._load_config_from_env(env)
         assert config["cmake_toolchain_file"] == "/path/to/toolchain"
         assert config["meson_cross_file"] == "/path/to/crossfile"
         assert config["xbuildenv_path"] == "/path/to/xbuildenv"
+        assert config["ignored_build_requirements"] == "cmake foo bar"
 
     def test_load_config_from_file(
         self, tmp_path, dummy_xbuildenv, reset_env_vars, reset_cache
@@ -151,6 +155,7 @@ def test_load_config_from_file(
                                   meson_cross_file = "$(MESON_CROSS_FILE)"
                                   build_dependency_index_url = "https://example.com/simple"
                                   xbuildenv_path = "../my_custom/xbuildenv_path" # also helps check relative paths
+                                  ignored_build_requirements = "cmake foo bar"
                                   """)
 
         xbuildenv_manager = CrossBuildEnvManager(
@@ -169,6 +174,7 @@ def test_load_config_from_file(
         assert config["meson_cross_file"] == "/path/to/crossfile"
         assert config["build_dependency_index_url"] == "https://example.com/simple"
         assert config["xbuildenv_path"] == "../my_custom/xbuildenv_path"
+        assert config["ignored_build_requirements"] == "cmake foo bar"
 
     def test_config_all(self, dummy_xbuildenv, reset_env_vars, reset_cache):
         xbuildenv_manager = CrossBuildEnvManager(

pyodide_build/tests/test_pypabuild.py

@@ -1,4 +1,5 @@
 from pyodide_build import pypabuild, pywasmcross
+from pyodide_build.constants import BASE_IGNORED_REQUIREMENTS
 
 
 class MockIsolatedEnv:
@@ -27,8 +28,8 @@ def test_install_reqs(tmp_path, dummy_xbuildenv):
     for req in reqs:
         assert req in env.installed
 
-    pypabuild.install_reqs({}, env, set(pypabuild.AVOIDED_REQUIREMENTS))  # type: ignore[arg-type]
-    for req in pypabuild.AVOIDED_REQUIREMENTS:
+    pypabuild.install_reqs({}, env, set(BASE_IGNORED_REQUIREMENTS))  # type: ignore[arg-type]
+    for req in BASE_IGNORED_REQUIREMENTS:
         assert req not in env.installed