sniffio._impl.AsyncLibraryNotFoundError: unknown async library, or not in async context

[dimaqq]

So I wrote some code that calls:
my code -> httpx -> httpcore -> anyio -> sniffio

When I run it "in production", using asyncio.run(start()) it's all fine.

But then I try to start it in testing, using:

@pytest_asyncio.fixture
async def mything(...):
    task = asyncio.create_task(mything.start())
    yield task
    task.cancel()

sniffio bails with unknown async library, or not in async context

I'm not quite sure how to debug this... is there something special about the testing event loop?

[dimaqq]

In case someone hits this: apparently it's when the task is cancelled too soon for sniffio to make the detection, I should've known that surely it's not this library fault!

[aleksandaratanasov]

And the solution is? I mean I am writing an async client based on HTTPX that uses an AsyncIO event loop to handle sending and retrieving info. Since I am at the beginning, I cannot artificially stall the call so I get this error whenever I call my __del__(self), where I call the loop to close the HTTPX async client and then stop the loop.