Reproduction for mypy 8481

__init__.pyi

from .user import User as User, ClientUser as ClientUser
from .channel import *
from .message import Message as Message
from . import abc

abc.pyi

import abc

from .message import Message
from typing import Optional, Any
from typing_extensions import Protocol, runtime

class GuildChannel: ...

class Messageable(metaclass=abc.ABCMeta):
    async def send(
        self,
        content=None,
        *,
        tts=False,
        embed=None,
        file=None,
        files=None,
        delete_after=None,
        nonce=None,
        allowed_mentions=None
    ) -> Message: ...

@runtime
class User(Protocol):
    name: str
    discriminator: str
    avatar: Optional[str]
    bot: bool
    @property
    @abc.abstractmethod
    def display_name(self) -> str: ...
    @property
    @abc.abstractmethod
    def mention(self) -> str: ...

channel.pyi

import repro.abc
from .message import Message
from .user import BaseUser, User, ClientUser
from typing import Optional, Any, List

class TextChannel(repro.abc.Messageable): ...

class DMChannel(repro.abc.Messageable):
    recipient: User
    me: ClientUser
    def permissions_for(self, user: Optional[BaseUser] = ...) -> Any: ...

class GroupChannel(repro.abc.Messageable):
    me: ClientUser
    owner: User
    def permissions_for(self, user: BaseUser) -> Any: ...
    async def add_recipients(self, *recipients: User) -> None: ...
    async def remove_recipients(self, *recipients: User) -> None: ...

class CategoryChannel(repro.abc.GuildChannel): ...

message.pyi

from .channel import TextChannel, DMChannel, GroupChannel
from typing import Union

class Message:
    channel: Union[TextChannel, DMChannel, GroupChannel]

user.pyi

import repro.abc

from .message import Message
from typing import Optional, Any, List

_BaseUser = repro.abc.User

class BaseUser(_BaseUser):
    name: str
    discriminator: str
    avatar: Optional[str]
    bot: bool
    @property
    def mention(self) -> str: ...
    @property
    def display_name(self) -> str: ...

class ClientUser(BaseUser):
    @property
    def friends(self) -> List[User]: ...
    @property
    def blocked(self) -> List[User]: ...

class User(BaseUser, repro.abc.Messageable): ...