false positive on interaction between @property, @lru_cache, and inheritance

[finite-state-machine]

Bug Report

My thanks to @hauntsaninja for their excellent work on #5858! However, I suspect there's a related issue with the combination of @lru_cache and @property where inheritance is at play:

To Reproduce

Gists:
mypy-play.net
pyright-play.net (pyright handles this correctly, IMO)

from __future__ import annotations
from abc import ABC, abstractmethod
from functools import lru_cache

class AlfaBase(ABC):
    # (base class is shown as abstract, but it doesn't matter)
    @property
    @abstractmethod
    def meaning_of_life(self) -> int: ...

class AlfaImpl(AlfaBase):

    @property
    @lru_cache(maxsize=None)
    def meaning_of_life(self) -> int:     # ←───┐
        # (deep thought)                  #     │
        return 42                         #     │
                                          #     │
# actual behavior:  (here)──────────────────────┘
#
#   Signature of "meaning_…" incompatible with supertype "AlfaBase" [override]
#       Superclass:
#           int
#       Subclass:
#           _lru_cache_wrapper[int]
#
# expected: (no error)


# (without inheritance, everything works as it should:)

class BravoImpl:

    @property
    @lru_cache(maxsize=None)
    def meaning_of_life(self) -> int:  # no errors (as expected)
        return 42

Expected Behavior

The tool should accept the code without comment.

Actual Behavior

The tool believes the type of the inherited @property is incompatible with the definition in the base class.

Your Environment

• Mypy version used: 1.8.0, master (2024-02-01)
• Mypy command-line flags: none
• Mypy configuration options from mypy.ini (and other config files): none
• Python version used: 3.8, 3.12

[hauntsaninja]

Thanks, looks easy enough to fix #16856

[finite-state-machine]

Amazingly quick. Thanks again!

[hauntsaninja]

I went ahead and merged my PR, but note there's a (pre-existing) false negative: #16857