Incorrect type hints for custom classes named Sequence, Union, etc

[markuspi]

Defining a custom pybind11 class that is named Sequence, Union, or other classes from the typing package leads to incorrectly generated signatures:

#include <pybind11/pybind11.h>
#include <pybind11/cast.h>

namespace py = pybind11;
using namespace pybind11::literals;

class Sequence {
  public:
  Sequence(int x) {}
};

PYBIND11_MODULE(sandbox, m)
{
  py::class_<Sequence>(m, "Sequence") //
    .def(py::init<int>(), "x"_a);
}

pybind11-stubgen incorrectly annotated the CTOR as self: typing.Sequence, x: int instead of self, x: int or at least self: Sequence, x: int

from __future__ import annotations
import typing
__all__ = ['Sequence']
class Sequence:
    def __init__(self: typing.Sequence, x: int) -> None:
        ...

Note that the original docstring __init__(self: sandbox.Sequence, x: int) contains the fully qualified class name, which would in theory allow more fine-grained differentiation between custom classes and classes from the standard library:

$ python -c "import sandbox; print(help(sandbox.Sequence))"

Help on class Sequence in module sandbox:

class Sequence(pybind11_builtins.pybind11_object)
 |  Method resolution order:
 |      Sequence
 |      pybind11_builtins.pybind11_object
 |      builtins.object
 |
 |  Methods defined here:
 |
 |  __init__(...)
 |      __init__(self: sandbox.Sequence, x: int) -> None
 |
 |  ----------------------------------------------------------------------
 |  Static methods inherited from pybind11_builtins.pybind11_object:
 |
 |  __new__(*args, **kwargs) class method of pybind11_builtins.pybind11_object
 |      Create and return a new object.  See help(type) for accurate signature.