False positive dataclass inheritance error for frozen models

[krmozejko]

Describe the bug
For models inheriting from BaseModel configured as frozen with class argument I get false errors:
Frozen dataclasses can not inherit non-frozen one and vice versa

Steps to reproduce
Define frozen model using class argument.

from pydantic import BaseModel


class Foo(BaseModel, frozen=True):
    a: str

Expected behavior
Error should not be visible.

Screenshots

Environments (please complete the following information):

• IDE PyCharm 2025.2.1 (Community Edition)
• OS: macOS 15.6.1
• Pydantic Version: 2.10.6
• Plugin version: 0.4.19

Additional context
Add any other context about the problem here.

[mrpiggi]

I noticed the same. As a workaround, you can use

class Foo(BaseModel):
    model_config = ConfigDict(frozen=True)

    a: str

or for convenience

class FrozenBaseModel(BaseModel):
    model_config = ConfigDict(frozen=True)

class Foo(FrozenBaseModel):
    a: str