ModuleNotFoundError: No module named 'setuptools._distutils'

[dHannasch]

Environment

• pip version: 20.2
• Python version: 3.7.1
• OS: Ubuntu 16.04 (Travis)

Description

pip install . crashes.

This might be due to pip installing setuptools 50.0.0 into the pip-build-env. If it were possible to tell pip not to use the latest setuptools, that might work as a workaround while setuptools figures out the underlying problem. But based on what I'm learning, it appears there's no way to directly meddle with what setuptools pip installs into the pip-build-env, which means that pip breaks completely when there's a bug in the latest released version of setuptools, with no ability to fall back to an old vesion.

Expected behavior

pip install . should not crash.

How to Reproduce

1. Get package from https://github.com/dHannasch/tox-sitepackages-example (or any number of other repositories, it's not specific to that package, it was first observed elsewhere)
2. Then run pip install . Or just run the CI on Travis, which runs the commands in .travis.yml.
3. ModuleNotFoundError: No module named 'setuptools._distutils'

Output

python -m pip install .

Processing /home/travis/build/dHannasch/tox-sitepackages-example

  Installing build dependencies ... done

  Getting requirements to build wheel ... done

ERROR: Exception:

Traceback (most recent call last):

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/cli/base_command.py", line 216, in _main

    status = self.run(options, args)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/cli/req_command.py", line 182, in wrapper

    return func(self, options, args)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/commands/install.py", line 325, in run

    reqs, check_supported_wheels=not options.target_dir

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/resolution/legacy/resolver.py", line 183, in resolve

    discovered_reqs.extend(self._resolve_one(requirement_set, req))

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/resolution/legacy/resolver.py", line 388, in _resolve_one

    abstract_dist = self._get_abstract_dist_for(req_to_install)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/resolution/legacy/resolver.py", line 340, in _get_abstract_dist_for

    abstract_dist = self.preparer.prepare_linked_requirement(req)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 483, in prepare_linked_requirement

    req, self.req_tracker, self.finder, self.build_isolation,

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/operations/prepare.py", line 91, in _get_prepared_distribution

    abstract_dist.prepare_distribution_metadata(finder, build_isolation)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/distributions/sdist.py", line 38, in prepare_distribution_metadata

    self._setup_isolation(finder)

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_internal/distributions/sdist.py", line 96, in _setup_isolation

    reqs = backend.get_requires_for_build_wheel()

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_vendor/pep517/wrappers.py", line 161, in get_requires_for_build_wheel

    'config_settings': config_settings

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_vendor/pep517/wrappers.py", line 265, in _call_hook

    raise BackendUnavailable(data.get('traceback', ''))

pip._vendor.pep517.wrappers.BackendUnavailable: Traceback (most recent call last):

  File "/home/travis/build/dHannasch/tox-sitepackages-example/py38/lib/python3.7/site-packages/pip/_vendor/pep517/_in_process.py", line 86, in _build_backend

    obj = import_module(mod_path)

  File "/opt/python/3.7.1/lib/python3.7/importlib/__init__.py", line 127, in import_module

    return _bootstrap._gcd_import(name[level:], package, level)

  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import

  File "<frozen importlib._bootstrap>", line 983, in _find_and_load

  File "<frozen importlib._bootstrap>", line 953, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed

  File "<frozen importlib._bootstrap>", line 1006, in _gcd_import

  File "<frozen importlib._bootstrap>", line 983, in _find_and_load

  File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 677, in _load_unlocked

  File "<frozen importlib._bootstrap_external>", line 728, in exec_module

  File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed

  File "/opt/python/3.7.1/lib/python3.7/site-packages/setuptools/__init__.py", line 5, in <module>

    import distutils.core

  File "/tmp/pip-build-env-co0toouh/overlay/lib/python3.7/site-packages/_distutils_hack/__init__.py", line 82, in create_module

    return importlib.import_module('._distutils', 'setuptools')

  File "/opt/python/3.7.1/lib/python3.7/importlib/__init__.py", line 127, in import_module

    return _bootstrap._gcd_import(name[level:], package, level)

ModuleNotFoundError: No module named 'setuptools._distutils'```

[uranusjr]

Feels like a setuptools bug at first glance, not pip.

[vkrot-exos]

Had same issue, looks like setuptools problem - pypa/setuptools#2353

[dHannasch]

I thought I was pretty explicit that this is a setuptools 50 problem? The problem is that setuptools 50 is being installed.

In any case, @vkrot-exos found a workaround: just change pypyoject.toml to use setuptools<50. So there is a workaround, so there's nothing we need from pip. Leaving this here for anyone who comes here searching for the same problem.

[godlygeek]

I believe this is a pip bug; see #6264 (comment).

[AkashicSeer]

Wow I truly have a knack for finding every problem with everything I touch.