setuptools 50 fails with `KeyError: 'distutils'` when installing some packages

I got the following error when tried to install doit.

$ pip install doit
Collecting doit
  Using cached doit-0.32.0.tar.gz (1.4 MB)
    ERROR: Command errored out with exit status 1:
     command: /home/enki/projects/.../.venv/bin/python3.6 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/tmp/pip-install-t_g4mfyi/doit/setup.py'"'"'; __file__='"'"'/tmp/pip-install-t_g4mfyi/doit/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /tmp/pip-pip-egg-info-shhwaq7f
         cwd: /tmp/pip-install-t_g4mfyi/doit/
    Complete output (17 lines):
    /home/enki/projects/.../.venv/lib/python3.6/site-packages/_distutils_hack/__init__.py:30: UserWarning: Setuptools is replacing distutils.
      warnings.warn("Setuptools is replacing distutils.")
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-install-t_g4mfyi/doit/setup.py", line 88, in <module>
        'doit = doit.__main__:main'
      File "/home/enki/projects/.../.venv/lib/python3.6/site-packages/setuptools/__init__.py", line 152, in setup
        _install_setup_requires(attrs)
      File "/home/enki/projects/.../.venv/lib/python3.6/site-packages/setuptools/__init__.py", line 145, in _install_setup_requires
        dist.parse_config_files(ignore_option_errors=True)
      File "/home/enki/projects/.../.venv/lib/python3.6/site-packages/setuptools/dist.py", line 665, in parse_config_files
        self._parse_config_files(filenames=filenames)
      File "/home/enki/projects/.../.venv/lib/python3.6/site-packages/setuptools/dist.py", line 572, in _parse_config_files
        filenames = self.find_config_files()
      File "/home/enki/projects/.../.venv/lib/python3.6/site-packages/setuptools/_distutils/dist.py", line 353, in find_config_files
        sys_dir = os.path.dirname(sys.modules['distutils'].__file__)
    KeyError: 'distutils'
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

[asfaltboy]

Could this be a side-effect of overriding distutils on stdlib the as described in #2350? I’ll try to confirm the workaround (using SETUPTOOLS_USE_DISTUTILS=1 works and report back).

EDIT: the workaround worked fine, as long as I run it before installing python via apt-get / get-pip installations .

[jaraco]

According to using pip in your program, import pip is not supported anywhere.

#2381 takes some steps to avoid breaking under the conditions where pip is imported.

And if it’s not supported, should it simply fail (maybe with some environment detection) instead of asking why people uses an unsupported code later?

Perhaps that’s a question for the pip maintainers. My instinct is that users should be allowed to “import pip” at their own risk, so it shouldn’t be strictly enforced.