Repository navigation
Unreachable match wildcard case is not reported #20251
Description
Bug Report
When a match statement on an enum is already exhaustive, mypy does not consider the wildcard case to be unreachable.
To Reproduce
from enum import Enum, auto
class Thing(Enum):
ONE = auto()
def main(foo: Thing) -> None:
match foo:
case Thing.ONE:
pass
case _:
passExpected Behavior
The wildcard case is unreachable and should be reported as an error.
Actual Behavior
Success: no issues found in 1 source file
Your Environment
- Mypy version used: 1.18.2
- Mypy command-line flags:
--warn-unreachable --enable-error-code=exhaustive-match - Python version used: 3.14
Activity
A5rocks commentedon Nov 18, 2025
Possible duplicate of #20142 though single-value enum logic is sometimes different (sadly).
A5rocks commentedon Nov 18, 2025
Hmm maybe if you replace
passwith egprint("hi")it might warn about unreachability? Mypy doesn't flagpassfor unreachability...(I cannot check right now)
injust commentedon Nov 18, 2025
Yup, that triggered the unreachability error.
I guess this is working as intended then?
A5rocks commentedon Nov 18, 2025
Yeah