The following crashes the interpreter in Python 3.11, and works fine in older versions:

# --- script.py 
import types

class MyModule (types.ModuleType):
    __slots__ = (
        "_MyModule__a",
        "_MyModule__b",
    )

    def __init__(self, name):
        super().__init__(name)

m = MyModule("name")
# -- end of file

The key in this is the ``__slots__`` definition: The script does not crash without ``__slots__``, or with a slots tuple with 1 item.

This is a reproducer based on code in PyObjC.