The following code:

class ComparableNumber[T: ComparableNumber](Protocol):
    def __lt__(self, other: T, /) -> bool: ...
    def __gt__(self, other: T, /) -> bool: ...
    def __int__(self) -> int: ...

Fails with:

_typing.py:15: error: Cannot resolve name "ComparableNumber" (possible cyclic definition)  [misc]

Pyright seems to accept it with no issue and python itself doesn't complain or raise any exception when this definition is loaded at runtime.

This is with the current head version from github with default configuration, no command line switches and with

# mypy: enable-incomplete-feature=NewGenericSyntax

being used in the file where this is defined.