New version of virtualenv causes ModuleNotFoundError: No module named 'setuptools'

[forkerino]

describe your issue

Our pre-commit CI step started failing with this error, and we can see that it now uses virtualenv 20.11.0 instead of 20.10.0 (started failing soon as they released 20.11.0). Changelog mentions:

Upgrade embedded setuptools to 59.4.0 from 58.3.0

full output:

An unexpected error has occurred: CalledProcessError: command: ('/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/bin/python', '-mpip', 'install', '.')
return code: 2
expected return code: 0
stdout:
Processing /home/runner/.cache/pre-commit/repo59pjdrh5
Installing build dependencies: started
Installing build dependencies: finished with status 'done'
Getting requirements to build wheel: started
Getting requirements to build wheel: finished with status 'done'

stderr:
ERROR: Exception:
Traceback (most recent call last):
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/cli/base_command.py", line 164, in exc_logging_wrapper
status = run_func(*args)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/cli/req_command.py", line 205, in wrapper
return func(self, options, args)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/commands/install.py", line 338, in run
requirement_set = resolver.resolve(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/resolver.py", line 73, in resolve
collected = self.factory.collect_root_requirements(root_reqs)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/factory.py", line 468, in collect_root_requirements
req = self._make_requirement_from_install_req(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/factory.py", line 430, in _make_requirement_from_install_req
cand = self._make_candidate_from_link(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/factory.py", line 201, in _make_candidate_from_link
self._link_candidate_cache[link] = LinkCandidate(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 281, in init
super().init(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 156, in init
self.dist = self._prepare()
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 225, in _prepare
dist = self._prepare_distribution()
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 292, in _prepare_distribution
return preparer.prepare_linked_requirement(self._ireq, parallel_builds=True)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 482, in prepare_linked_requirement
return self._prepare_linked_requirement(req, parallel_builds)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 546, in _prepare_linked_requirement
dist = _get_prepared_distribution(
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 58, in _get_prepared_distribution
abstract_dist.prepare_distribution_metadata(finder, build_isolation)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 47, in prepare_distribution_metadata
self._install_build_reqs(finder)
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 106, in _install_build_reqs
build_reqs = self._get_build_requires_wheel()
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 83, in _get_build_requires_wheel
return backend.get_requires_for_build_wheel()
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_vendor/pep517/wrappers.py", line 172, in get_requires_for_build_wheel
return self._call_hook('get_requires_for_build_wheel', {
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_vendor/pep517/wrappers.py", line 332, in _call_hook
raise BackendUnavailable(data.get('traceback', ''))
pip._vendor.pep517.wrappers.BackendUnavailable: Traceback (most recent call last):
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 89, in _build_backend
obj = import_module(mod_path)
File "/opt/hostedtoolcache/Python/3.9.9/x64/lib/python3.9/importlib/init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "", line 1030, in _gcd_import
File "", line 1007, in _find_and_load
File "", line 986, in _find_and_load_unlocked
File "", line 680, in _load_unlocked
File "", line 850, in exec_module
File "", line 228, in _call_with_frames_removed
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/masonry/api.py", line 1, in
from poetry.core.masonry.api import build_sdist
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/core/masonry/init.py", line 10, in
from .builder import Builder
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/core/masonry/builder.py", line 7, in
from .builders.sdist import SdistBuilder
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/core/masonry/builders/init.py", line 2, in
from .wheel import WheelBuilder
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/core/masonry/builders/wheel.py", line 23, in
from packaging.tags import sys_tags
File "/tmp/pip-build-env-rf7ihm0k/overlay/lib/python3.9/site-packages/poetry/core/_vendor/packaging/tags.py", line 7, in
import distutils.util
File "/home/runner/.cache/pre-commit/repo59pjdrh5/py_env-python3.9/lib/python3.9/site-packages/_distutils_hack/init.py", line 92, in create_module
return importlib.import_module('setuptools._distutils')
File "/opt/hostedtoolcache/Python/3.9.9/x64/lib/python3.9/importlib/init.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
ModuleNotFoundError: No module named 'setuptools'

pre-commit --version

2.9.2

.pre-commit-config.yaml

we use:
- black
- isort
- flake8
- eslint
- debug linter
- mypy
- semgrep

~/.cache/pre-commit/pre-commit.log (if present)

No response

[FollowTheProcess]

We're getting this with Nox too, initially discovered in wntrblm/nox#545 and seemingly fixed by pinning virtualenv to 20.10.0 in wntrblm/nox#547

Just as an extra confirmational data point 🙂

[asottile]

please follow up at pypa/virtualenv

[asottile]

here's the relevant things to follow up on:

• ModuleNotFoundError: No module named 'setuptools._distutils' pypa/setuptools#2353
• virtualenv with --system-site-packages breaks pip's build isolation pypa/pip#6264
• setuptools 60: "No module named 'setuptools'" when installing Poetry from source pypa/setuptools#2980

why we're suddenly seeing this:

• the latest virtualenv release upgraded setuptools to 60.1.0 (despite what the changelog says it was upgraded to 60.1.0 here)
• setuptools 60.* changes the default to using the setuptools-embedded distutils rather than the stdlib distutils
• setuptools does this by way of a .pth file which redirects imports of distutils to setuptools._distutils
• during pip's isolated builds (triggered by pyproject.toml, for example to install isort via poetry) pip attempts to clear the current sys.path of the enclosing environment and isolates to the pyproject.toml-installed build dependencies, but it's a bit too late as the .pth files from the enclosing environment are applied. so in this environment setuptools is not installed, but its import hooks are

workarounds:

• avoid installing virtualenv==20.11.0 (will begin failing soon due to periodic update)
• set SETUPTOOLS_USE_DISTUTILS=stdlib to avoid the local default

I don't have any say on the upstream projects, but my recommendation would be to:

• yank virtualenv==20.11.0 to avoid automatic unpinned installation of that
• fix pip to have proper build isolation against the parent site -- something like this hack or use actual virtual environments to perform isolated builds
• (optional) until pip is released with a fix, revert back to =stdlib as the default in setuptools

reproducing this outside of pre-commit / without latest virtualenv / without virtualenv

python3 -m venv venv
venv/bin/pip install setuptools==60.1.0 pip==21.3.1
venv/bin/pip install --no-binary :all: isort==5.10.1

[gaborbernat]

• avoid installing virtualenv==20.11.0

Note virtualenv will upgrade (by default) to setuptools 60.1.0 even on older versions within 28 days of the release, so on 21st of January. So this is not really a fix, more like a quick workaround. This will happen sooner if someone manually runs --upgrade-embed-wheels. For this reason I'll not yank virtualenv, because that would not really fix the problem anyway.