Type annotations not hyperlinked with class keyword argument

[alexfikl]

Describe the bug

When rendering the following snippet

def convert_dtype_v1(a: Any, *, dtype: Any = np.int32) -> Any:
    return a.astype(dtype)

the typing annotations are all shown as ~typing.Any and no hyperlinks are generated. The issue seems to be with the np.int32 default argument. As far as I've been able to debug it, it goes through the following steps

• a string is generated for the signature that contains repr(np.int32).
• the string is passed to signature_from_str in

  sphinx/sphinx/util/inspect.py

  Line 700 in 2f60b44

  def signature_from_str(signature: str) -> inspect.Signature:

• ast.parse throws a SyntaxError due to the <class 'numpy.int32'>.
• handle_signature proceeds to skip the parsing at

  sphinx/sphinx/domains/python.py

  Line 517 in 2f60b44

  except SyntaxError:

Ideally the type annotations would be rendered and hyperlinked correctly.

How to Reproduce

sphinx-bug-mre.tar.gz contains a minimal example that can be built with the usual

$ sphinx-build -M html . _build
$ # open _build/html/index and see bla bla

On my machine, this results in the rendering below. v0 is rendered as expected, while v1 has all the types as plaintext.

Environment Information

Platform:              linux; (Linux-6.0.6-arch1-1-x86_64-with-glibc2.36) 
Python version:        3.10.8 (main, Oct 13 2022, 21:13:48) [GCC 12.2.0]) 
Python implementation: CPython 
Sphinx version:        5.3.0 
Docutils version:      0.19 
Jinja2 version:        3.1.2

Sphinx extensions

sphinx.ext.autodoc; sphinx.ext.intersphinx

Additional context

No response