stubgen failed to find function signature from native modules

Feature

I have written a native module with a hand-written docstring and signature.
The signature is available via

import inspect
import mymod

inspect.signature(mymod.MyClass.method1)
# or
help(mymod.MyClass)
# correctly prints (a,b,c)

However stubgen -p mymod generates .pyi with

class Myclass:
  @classmethod
  def __init__(cls, *args, **kwargs) -> None: ...
  def method1(self, *args, **kwargs) -> Any: ...

filled with *args and **kwargs instead of correct signatures. (Worse, method1 is in fact staticmethod so vscode complains with this stub)

The binding is written with rust pyo3.
Since all inspect.signature, help, and IPython can read the signature, I think the problem is in stubgen.
I don't know the internals of stubgen, but would it help to use inspect.signature when other methods in generate_stub_for_c_module fail?

Start by reading stubgen's generate_stub_for_c_module path and compare its current signature-discovery fallbacks with inspect.signature on the native module example. Done means stubgen emits the documented parameter signatures and preserves method kinds such as staticmethod instead of using generic *args and **kwargs.