lifespan incompatible type

[dineshbvadhia]

First Check

• I added a very descriptive title here.
• I used the GitHub search to find a similar question and didn't find it.
• I searched the FastAPI documentation, with the integrated search.
• I already searched in Google "How to X in FastAPI" and didn't find any information.
• I already read and followed all the tutorial in the docs and didn't find an answer.
• I already checked if it is not related to FastAPI but to Pydantic.
• I already checked if it is not related to FastAPI but to Swagger UI.
• I already checked if it is not related to FastAPI but to ReDoc.

Commit to Help

• I commit to help with one of those options 👆

Example Code

async def lifespan(_: FastAPI) ->  AsyncGenerator[dict[str, str] | None, None]:
    async with CustomAsyncContextManager() as c:
	# startup stuff
	yield {'this' : that}
	# cleanup

app = FastAPI(lifespan=lifespan)	# L866

Description

I'm using a custom async context manager with lifespan. The program runs as expected but mypy returns this error:

mypy:
866: error: Argument "lifespan" to "FastAPI" has incompatible type "Callable[[FastAPI], AsyncGenerator[dict[str, Dao] | None, None]]"; expected "Callable[[FastAPI], AbstractAsyncContextManager[None]] | Callable[[FastAPI], AbstractAsyncContextManager[Mapping[str, Any]]] | None" [arg-type]

What does this mean?

Operating System

Windows

Operating System Details

No response

FastAPI Version

0.103.2

Pydantic Version

2.4.2

Python Version

Python 3.11.4

Additional Context

No response

[Kludex]

Duplicated #10413

[dineshbvadhia]

@Kludex Duplicate by mistake but won't accept deletion.

Is there an answer to the question? Thanks

[Kludex]

... It's duplicated. Please continue the conversation on the other discussion.