Dataclass inheritance cannot override final attribute

[nelsyeung]

Bug Report

Dataclass inheritance where both the parent and the child contain the same typing.Final attribute causes Cannot override final attribute. This is at least inconsistent with frozen=True. If I don't use typing.Final and use frozen=True, it works, even though both should be the same.

To Reproduce

https://mypy-play.net/?gist=09184eeaf7501d79abb0c890a7019ba3

import dataclasses
import typing as t

@dataclasses.dataclass
class Foo:
    v: t.Final[int] = 0

@dataclasses.dataclass
class Bar(Foo):
    v: t.Final[int] = 1

Expected Behavior

No error, as I'm just changing the default value.

Actual Behavior

main.py:10: error: Cannot override final attribute "v" (previously declared in base class "Foo")  [misc]
Found 1 error in 1 file (checked 1 source file)

Your Environment

• Mypy version used: 2.3.0
• Mypy command-line flags:
• Mypy configuration options from mypy.ini (and other config files):
• Python version used: 3.12

[Hmanbo]

Final and frozen=True don't appear to have identical semantics.

The typing spec explicitly says that final attributes cannot be
overridden in subclasses, and it also specifies that a Final field
in a dataclass is treated as an instance-level final attribute.

So I'm wondering whether the current mypy behavior may actually
be spec-compliant.