Incorrect linting with type parameters PEP695 (generic)

[wookayin]

Bug description

Python 3.12.0

Possibly sharing the same root cause as #9098 but I'm reporting as the behavior is different just in case (here no crashes, just incorrect results). It'd be great if pylint can support all the type parameters specification described in https://peps.python.org/pep-0695/.

def constrained[T: (str, bytes)](argument: T) -> T:
    return argument

(EDIT: removed the second example in edit because it's not valid)

Configuration

No pylintrc is used (under the default setting).

Command used

pylint 695.py --disable=C0114,C0116

(Note: C0114, C0116 are missing docstrings)

Pylint output

************* Module 695
695.py:1:43: E0602: Undefined variable 'T' (undefined-variable)
695.py:1:49: E0602: Undefined variable 'T' (undefined-variable)
695.py:1:16: W0612: Unused variable 'T' (unused-variable)

Expected behavior

There should be no E0602, W0612, E0602 warnings and errors. T in the parameter annotation is the generic type.

Pylint version

pylint 3.0.0
astroid 3.0.0
Python 3.12.0 | packaged by conda-forge | (main, Oct  3 2023, 08:36:57) [Clang 15.0.7 ]

OS / Environment

macOS and Linux

Additional dependencies

N/A

[DanielNoord]

@jacobtylerwalls do we have any idea how hard it is to support the new typing syntax for the variables checker?

[jacobtylerwalls]

I do think it's the same root cause as #9098. Not terribly difficult, just figuring out how to make assigned_stmts() return the correct thing. A few hours? (I'm traveling this week).

[jacobtylerwalls]

Turns out this is a distinct fix from the crash. The crash can be fixed in astroid; the false positives can be fixed in pylint. Patches coming up.