Class attribute in subclass inherits attribute docstring in Sphinx 5.0.1

[oscarbenjamin]

Describe the bug

As of Sphinx 5.0.1 the SymPy docs build gives lots of warnings like this:

docstring of sympy.polys.domains.field.Field.is_Field:14: WARNING: more than one target found for cross-reference 'is_Ring': sympy.polys.domains.domain.Domain.is_Ring, sympy.polys.domains.ring.Ring.is_Ring

Full output in CI can be seen here:
https://github.com/sympy/sympy/runs/6784391829?check_suite_focus=true

The problem seems to be that there is a class Domain which has a documented attribute is_Ring:
https://github.com/sympy/sympy/blob/a96dce8b55675a0529d9bed479e2569126e27149/sympy/polys/domains/domain.py#L245-L262
You can see that in the docs here:
https://docs.sympy.org/dev/modules/polys/domainsref.html#sympy.polys.domains.domain.Domain.is_Ring

Then there is a class Ring which is a subclass of Domain and changes the value of the class attribute but does not document it:
https://github.com/sympy/sympy/blob/a96dce8b55675a0529d9bed479e2569126e27149/sympy/polys/domains/ring.py#L13

In previous versions of Sphinx the Ring class would not show the is_Ring attribute:
https://docs.sympy.org/dev/modules/polys/domainsref.html#sympy.polys.domains.ring.Ring

Now with Sphinx 5.0.1 though it seems that the Sphinx build decides to document the Ring.is_Ring attribute with the docstring inherited from the superclass Domain. Then the see also references to is_Ring fail due to multiple targets.

How to Reproduce

$ git clone https://github.com/sympy/sympy.git
$ cd sympy/doc
$ pip install -r requirements.txt
$ make html
$ # open _build/html/modules/polys/domainsref.html

Expected behavior

The attribute is_Ring in the subclass Ring would not be documented and there would be only one target for is_Ring pointing to the Domain.is_Ring attribute.

Your project

https://github.com/sympy/sympy

Screenshots

No response

OS

Any

Python version

3.8-3.10

Sphinx version

5.0.1

Sphinx extensions

Sphinx 5.0.1 sphinx-autobuild 2021.3.14 sphinx-basic-ng 0.0.1a11 sphinx-copybutton 0.5.0 sphinx-math-dollar 1.2.1 sphinx-press-theme 0.8.0 sphinx-reredirects 0.0.1 sphinxcontrib-applehelp 1.0.2 sphinxcontrib-devhelp 1.0.2 sphinxcontrib-htmlhelp 2.0.0 sphinxcontrib-jsmath 1.0.1 sphinxcontrib-qthelp 1.0.3 sphinxcontrib-serializinghtml 1.1.5

Extra tools

No response

Additional context

No response

[oscarbenjamin]

Actually it seems that this is maybe caused by an update to myst-parser 0.18.0:
sympy/sympy#23598

I'm not sure where the bug is here so maybe it's not actually in Shpinx...

[oscarbenjamin]

I've opened an issue with myst-parser:
executablebooks/MyST-Parser#583

I'm not sure if this is actually a bug in myst-parser rather than sphinx but I can confirm that actually it is the update to myst-parser 0.18.0 that has triggered the problem.

[oscarbenjamin]

Oh, I see. Changing the myst-parser version changes the Sphinx version as well. I've confirmed that forcing sphinx to be 5.0.1 while keeping myst-parser at 0.17.2 still reproduces the problem so it's definitely a Sphinx problem.

[AA-Turner]

Does it reproduce on 5.0.0 or 4.5.x? If it's a regression between 5.0.0 and 5.0.1 that's a much smaller set of changes to look for the problem in!

A

[oscarbenjamin]

The problem is also present in Sphinx 5.0.0 but is not present in 4.5.0 so it seems to be a regression in between 4.5.0 and 5.0.0.

[oscarbenjamin]

Bisected to efa6197 from #10447.

CC @akruis

[tk0miya]

Fixed by #10539. Thank you for reporting!

[oscarbenjamin]

Thanks both!