Repository navigation
False positive error "incompatible type" calling super() on a generic class with TypeVar constraints #14774
Description
Reduced test case (mypy-playground):
from typing import Generic, TypeVar
T = TypeVar("T", float, int)
class C(Generic[T]):
def __init__(self, i: T) -> None:
self.i: T = i
class B(C[T]):
def __init__(self, i: T) -> None:
super().__init__(i)main.py: note: In member "__init__" of class "B":
main.py:13:26: error: Argument 1 to "__init__" of "C" has incompatible type "float"; expected "T" [arg-type]
main.py:13:26: error: Argument 1 to "__init__" of "C" has incompatible type "int"; expected "T" [arg-type]
Found 2 errors in 1 file (checked 1 source file)
Originally posted by @leandro-lucarella-frequenz in #13566 (comment) (this is a very similar issue but not exactly the same)
Activity
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
Add a workaround for a mypy issue
bjoernpollex-sc commentedon Apr 13, 2026
I'm running into the same issue. I've also noticed that, if the types in the constraint are related, then using a bound instead of constraint fixes the issue.