astroid 2.13.0 uses typing_extensions on Python 3.10 but does not require it there

[andy-maier]

Steps to reproduce

In a virtual Python environment with Python 3.10 that does not have typing_extensions installed:

1. pip install pylint
2. pylint --version

This only happens on Python 3.10, not on <=3.9 or 3.11

Test runs with different OS and Python versions: https://github.com/pywbem/nocaselist/actions/runs/3864593150

Current behavior

Pylint fails with astroid trying to import from typing_extensions. However, typing_extensions is not installed because astroid 2.13.0 does not require it in its distribution on Python 3.10:

$ pylint --version
Traceback (most recent call last):
  File "/Users/maiera/virtualenvs/nocaselist310/bin/pylint", line 8, in <module>
    sys.exit(run_pylint())
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/__init__.py", line 32, in run_pylint
    from pylint.lint import Run as PylintRun
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/lint/__init__.py", line 19, in <module>
    from pylint.config.exceptions import ArgumentPreprocessingError
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/config/__init__.py", line 25, in <module>
    from pylint.config.arguments_provider import UnsupportedAction
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/config/arguments_provider.py", line 15, in <module>
    from pylint.config.arguments_manager import _ArgumentsManager
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/config/arguments_manager.py", line 25, in <module>
    from pylint import utils
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/utils/__init__.py", line 9, in <module>
    from pylint.utils.ast_walker import ASTWalker
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/pylint/utils/ast_walker.py", line 13, in <module>
    from astroid import nodes
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/astroid/__init__.py", line 46, in <module>
    from astroid import inference, raw_building
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/astroid/inference.py", line 18, in <module>
    from astroid import bases, constraint, decorators, helpers, nodes, protocols, util
  File "/Users/maiera/virtualenvs/nocaselist310/lib/python3.10/site-packages/astroid/constraint.py", line 19, in <module>
    from typing_extensions import Self
ModuleNotFoundError: No module named 'typing_extensions'

Expected behavior

should not fail

Looking at the requirement for typing_extensions in pyproject.toml and at the import in astroid/constraints.py, it seems that a mismatch of the Python version between those two for Python 3.10 is the reason for the issue.

python -c "from astroid import __pkginfo__; print(__pkginfo__.version)" output

This command does not work on Python 3.10 because of missing typing_extensions.
When installing typing_extensions manually, it shows:

2.13.0

pipdeptree -p pylint output

pylint==2.15.9
  - astroid [required: >=2.12.13,<=2.14.0-dev0, installed: 2.13.0]
    - lazy-object-proxy [required: >=1.4.0, installed: 1.9.0]
    - wrapt [required: >=1.11,<2, installed: 1.14.1]
  - dill [required: >=0.2, installed: 0.3.6]
  - isort [required: >=4.2.5,<6, installed: 5.11.4]
  - mccabe [required: >=0.6,<0.8, installed: 0.7.0]
  - platformdirs [required: >=2.2.0, installed: 2.6.2]
  - tomli [required: >=1.1.0, installed: 2.0.1]
  - tomlkit [required: >=0.10.1, installed: 0.11.6]

[DanielNoord]

@Pierre-Sassoulas Shall we release a hot fix and yank 2.13.0? This seems truly broken.

[Pierre-Sassoulas]

Yeah definitely. I'm on mobile right now so I can't release. Also thé maintenance branche is not ready sorry. But we Can release directly from main in this case

[DanielNoord]

I'm on mobile as well. No rush as it is the weekend and we haven't release pylint yet 😄

[mathiascode]

This doesn't seem to be fixed yet. typing-extensions isn't installed on Python 3.10 due to the Python version check here: https://github.com/PyCQA/astroid/blob/82b80d9c588e394afe9c61165b484a0944a4b352/pyproject.toml#L39

Sample job output:
https://github.com/nicotine-plus/nicotine-plus/actions/runs/3863997823/jobs/6591410278

[Pierre-Sassoulas]

Thank you for the head up @mathiascode, it was due to typing-extensions also being present in our tests requirements with laxer constraints hiding the issue, see #1944

[mathiascode]

Thanks for the fix, much appreciated!