# don't import any costly modules import sys import os is_pypy = '__pypy__' in sys.builtin_module_names def warn_distutils_present(): if 'distutils' not in sys.modules: return if is_pypy and sys.version_info < (3, 7): # PyPy for 3.6 unconditionally imports distutils, so bypass the warning # https://foss.heptapod.net/pypy/pypy/-/blob/be829135bc0d758997b3566062999ee8b23872b4/lib-python/3/site.py#L250 return import warnings warnings.warn( "Distutils was imported before Setuptools, but importing Setuptools " "also replaces the `distutils` module in `sys.modules`. This may lead " "to undesirable behaviors or errors. To avoid these issues, avoid " "using distutils directly, ensure that setuptools is installed in the " "traditional way (e.g. not an editable install), and/or make sure " "that setuptools is always imported before distutils." ) def clear_distutils(): if 'distutils' not in sys.modules: return import warnings warnings.warn("Setuptools is replacing distutils.") mods = [ name for name in sys.modules if name == "distutils" or name.startswith("distutils.") ] for name in mods: del sys.modules[name] def enabled(): """ Allow selection of distutils by environment variable. """ which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'local') return which == 'local' def ensure_local_distutils(): import importlib clear_distutils() # With the DistutilsMetaFinder in place, # perform an import to cause distutils to be # loaded from setuptools._distutils. Ref #2906. with shim(): importlib.import_module('distutils') # check that submodules load as expected core = importlib.import_module('distutils.core') assert '_distutils' in core.__file__, core.__file__ assert 'setuptools._distutils.log' not in sys.modules def do_override(): """ Ensure that the local copy of distutils is preferred over stdlib. See https://github.com/pypa/setuptools/issues/417#issuecomment-392298401 for more motivation. """ if enabled(): warn_distutils_present() ensure_local_distutils() class _TrivialRe: def __init__(self, *patterns): self._patterns = patterns def match(self, string): return all(pat in string for pat in self._patterns) class DistutilsMetaFinder: def find_spec(self, fullname, path, target=None): # optimization: only consider top level modules and those # found in the CPython test suite. if path is not None and not fullname.startswith('test.'): return method_name = 'spec_for_{fullname}'.format(**locals()) method = getattr(self, method_name, lambda: None) return method() def spec_for_distutils(self): if self.is_cpython(): return import importlib import importlib.abc import importlib.util try: mod = importlib.import_module('setuptools._distutils') except Exception: # There are a couple of cases where setuptools._distutils # may not be present: # - An older Setuptools without a local distutils is # taking precedence. Ref #2957. # - Path manipulation during sitecustomize removes # setuptools from the path but only after the hook # has been loaded. Ref #2980. # In either case, fall back to stdlib behavior. return class DistutilsLoader(importlib.abc.Loader): def create_module(self, spec): mod.__name__ = 'distutils' return mod def exec_module(self, module): pass return importlib.util.spec_from_loader( 'distutils', DistutilsLoader(), origin=mod.__file__ ) @staticmethod def is_cpython(): """ Suppress supplying distutils for CPython (build and tests). Ref #2965 and #3007. """ return os.path.isfile('pybuilddir.txt') def spec_for_pip(self): """ Ensure stdlib distutils when running under pip. See pypa/pip#8761 for rationale. """ if sys.version_info >= (3, 12) or self.pip_imported_during_build(): return clear_distutils() self.spec_for_distutils = lambda: None @classmethod def pip_imported_during_build(cls): """ Detect if pip is being imported in a build script. Ref #2355. """ import traceback return any( cls.frame_file_is_setup(frame) for frame, line in traceback.walk_stack(None) ) @staticmethod def frame_file_is_setup(frame): """ Return True if the indicated frame suggests a setup.py file. """ # some frames may not have __file__ (#2940) return frame.f_globals.get('__file__', '').endswith('setup.py') def spec_for_sensitive_tests(self): """ Ensure stdlib distutils when running select tests under CPython. python/cpython#91169 """ clear_distutils() self.spec_for_distutils = lambda: None sensitive_tests = ( [ 'test.test_distutils', 'test.test_peg_generator', 'test.test_importlib', ] if sys.version_info < (3, 10) else [ 'test.test_distutils', ] ) for name in DistutilsMetaFinder.sensitive_tests: setattr( DistutilsMetaFinder, f'spec_for_{name}', DistutilsMetaFinder.spec_for_sensitive_tests, ) DISTUTILS_FINDER = DistutilsMetaFinder() def add_shim(): DISTUTILS_FINDER in sys.meta_path or insert_shim() class shim: def __enter__(self): insert_shim() def __exit__(self, exc, value, tb): _remove_shim() def insert_shim(): sys.meta_path.insert(0, DISTUTILS_FINDER) def _remove_shim(): try: sys.meta_path.remove(DISTUTILS_FINDER) except ValueError: pass if sys.version_info < (3, 12): # DistutilsMetaFinder can only be disabled in Python < 3.12 (PEP 632) remove_shim = _remove_shim