import sys import os import re import importlib import warnings 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 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 warnings.warn("Setuptools is replacing distutils.") mods = [name for name in sys.modules if re.match(r'distutils\b', name)] for name in mods: del sys.modules[name] def enabled(): """ Allow selection of distutils by environment variable. """ which = os.environ.get('SETUPTOOLS_USE_DISTUTILS', 'stdlib') return which == 'local' def ensure_local_distutils(): clear_distutils() distutils = importlib.import_module('setuptools._distutils') distutils.__name__ = 'distutils' sys.modules['distutils'] = distutils # sanity check that submodules load as expected core = importlib.import_module('distutils.core') assert '_distutils' in core.__file__, core.__file__ 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 DistutilsMetaFinder: def find_spec(self, fullname, path, target=None): if path is not None: return method_name = 'spec_for_{fullname}'.format(**locals()) method = getattr(self, method_name, lambda: None) return method() def spec_for_distutils(self): import importlib.abc import importlib.util class DistutilsLoader(importlib.abc.Loader): def create_module(self, spec): return importlib.import_module('setuptools._distutils') def exec_module(self, module): pass return importlib.util.spec_from_loader('distutils', DistutilsLoader()) def spec_for_pip(self): """ Ensure stdlib distutils when running under pip. See pypa/pip#8761 for rationale. """ if self.pip_imported_during_build(): return clear_distutils() self.spec_for_distutils = lambda: None @staticmethod def pip_imported_during_build(): """ Detect if pip is being imported in a build script. Ref #2355. """ import traceback return any( frame.f_globals['__file__'].endswith('setup.py') for frame, line in traceback.walk_stack(None) ) DISTUTILS_FINDER = DistutilsMetaFinder() def add_shim(): sys.meta_path.insert(0, DISTUTILS_FINDER) def remove_shim(): try: sys.meta_path.remove(DISTUTILS_FINDER) except ValueError: pass