setuptools 60: "No module named 'setuptools'" when installing Poetry from source

setuptools version

60.0.0

Python version

3.9.6

OS

macOS 11.5.2

Additional environment information

No response

Description

Installing a package which uses a Poetry backend from source fails on 60.0.0. Poetry packages that I’ve tried (my own, as well as Poetry itself) fail to install. Package installs are successful after reverting to previous setuptools versions.

The changelog states that v60.0.0 introduces a breaking change:

pypa/setuptools#2896: Setuptools once again makes its local copy of distutils the default. To override, set SETUPTOOLS_USE_DISTUTILS=stdlib.

When using the environment variable as suggested, the package installs are again successful.

I tried a few flit and setuptools projects and observed no issues with those.

Expected behavior

The package should install without error.

How to Reproduce

Poetry itself uses poetry as a build tool, so installing poetry from source fails.

pip install --upgrade pip setuptools==60.0.0
unset SETUPTOOLS_USE_DISTUTILS
pip install git+ssh://[e-mail]/python-poetry/poetry

Alternatively, clone poetry and run pip install . locally inside the repo.

Output

pip install git+ssh://[e-mail]/python-poetry/poetry

pip install git+ssh://[e-mail]/python-poetry/poetry
Collecting git+ssh://****@github.com/python-poetry/poetry
  Cloning ssh://****@github.com/python-poetry/poetry to /private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-req-build-oq1rbxm7
  Running command git clone --filter=blob:none -q 'ssh://****@github.com/python-poetry/poetry' /private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-req-build-oq1rbxm7
  Resolved ssh://****@github.com/python-poetry/poetry to commit 6a35cc41e950d4ff0f1efad649c1d15d689a9ce2
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
ERROR: Exception:
Traceback (most recent call last):
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/cli/base_command.py", line 164, in exc_logging_wrapper
    status = run_func(*args)
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/cli/req_command.py", line 205, in wrapper
    return func(self, options, args)
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/commands/install.py", line 338, in run
    requirement_set = resolver.resolve(
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/resolver.py", line 73, in resolve
    collected = self.factory.collect_root_requirements(root_reqs)
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 281, in __init__
    super().__init__(
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 156, in __init__
    self.dist = self._prepare()
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/resolution/resolvelib/candidates.py", line 225, in _prepare
    dist = self._prepare_distribution()
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/operations/prepare.py", line 546, in _prepare_linked_requirement
    dist = _get_prepared_distribution(
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 47, in prepare_distribution_metadata
    self._install_build_reqs(finder)
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_internal/distributions/sdist.py", line 106, in _install_build_reqs
    build_reqs = self._get_build_requires_wheel()
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/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 "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/pip/_vendor/pep517/in_process/_in_process.py", line 89, in _build_backend
    obj = import_module(mod_path)
  File "/usr/local/Cellar/python@3.9/3.9.6/Frameworks/Python.framework/Versions/3.9/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 972, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1030, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1007, in _find_and_load
  File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 680, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 850, in exec_module
  File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed
  File "/private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-build-env-hp7wsna4/overlay/lib/python3.9/site-packages/poetry/core/masonry/__init__.py", line 10, in <module>
    from .builder import Builder
  File "/private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-build-env-hp7wsna4/overlay/lib/python3.9/site-packages/poetry/core/masonry/builder.py", line 7, in <module>
    from .builders.sdist import SdistBuilder
  File "/private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-build-env-hp7wsna4/overlay/lib/python3.9/site-packages/poetry/core/masonry/builders/__init__.py", line 2, in <module>
    from .wheel import WheelBuilder
  File "/private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-build-env-hp7wsna4/overlay/lib/python3.9/site-packages/poetry/core/masonry/builders/wheel.py", line 23, in <module>
    from packaging.tags import sys_tags
  File "/private/var/folders/k6/2dzjkwsd1mj8m52xz1b2swym0000gp/T/pip-build-env-hp7wsna4/overlay/lib/python3.9/site-packages/poetry/core/_vendor/packaging/tags.py", line 7, in <module>
    import distutils.util
  File "/Users/alkasm/prog/setuptools-60.0.0-install-error/venv/lib/python3.9/site-packages/_distutils_hack/__init__.py", line 92, in create_module
    return importlib.import_module('setuptools._distutils')
  File "/usr/local/Cellar/python@3.9/3.9.6/Frameworks/Python.framework/Versions/3.9/lib/python3.9/importlib/__init__.py", line 127, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ModuleNotFoundError: No module named 'setuptools'

Code of Conduct

• I agree to follow the PSF Code of Conduct

[jaraco]

Released as 60.1.1. Please test and let me know if there are outstanding issues.

[jaraco]

Thanks for the report. In this case, I’d like someone from the poetry project to help triage and ascertain what’s going wrong in Setuptools that’s triggering issues in poetry. I can likely help debug after I deal with another emergent issue on Ubuntu.