Sphinx v7.4.0: Failed to get a method signature: unhashable type

[sphuber]

Describe the bug

When installing sphinx=7.4.0 that was just released, using the typing.ParamSpec results in the following warning:

WARNING: Failed to get a method signature for thing.ProcessFunctionType.run: unhashable type: 'ParamSpecArgs'

How to Reproduce

conf.py

import os
import sys
sys.path.insert(0, os.path.abspath('../src'))

extensions = ['sphinx.ext.autodoc']

index.rst

.. automodule:: thing
   :members:

The following source file

import typing as t

P = t.ParamSpec('P')
R_co = t.TypeVar('R_co', covariant=True)
N = t.TypeVar('N', bound=str)


class ProcessFunctionType(t.Protocol, t.Generic[P, R_co, N]):
    """Protocol type."""

    def run(self, *args: P.args, **kwargs: P.kwargs) -> R_co:
        """Some method."""

compiled with Sphinx v7.4

Environment Information

Only happens for `sphinx==7.4.0`. Builds fine with older versions

Sphinx extensions

sphinx.ext.autodoc

Additional context

No response

[AA-Turner]

@sphuber please can you provide the index.rst and the conf.py for the minimal example?

[sphuber]

@AA-Turner done

[AA-Turner]

Simpler reproducer:

from typing import ParamSpec

from sphinx.util.typing import stringify_annotation

def test_stringify_paramspec():
    P = ParamSpec('P')
    stringify_annotation(P.args, 'smart')
    stringify_annotation(P.kwargs, 'smart')

The first issue is that ParamSpecArgs isn't hashable, and hence annotation in {None, NoneType} raises a TypeError. The second is that ParamSpecArgs has no __name__ or __qualname__ (though it does have __module__). This will be slightly harder, though I admit I'm not sure why the name attributes don't exist.

A

[AA-Turner]

Sphinx 7.4.1 has been released with a fix.

A

[sphuber]

Can confirm that 7.4.1 fixes the issues, thanks a lot for the very quick resolution!

[AA-Turner]

Glad to be of service!

A