close_loop coroutine instantiated but never awaited in (old?) asyncio loop integration

[johnfb]

I was trawling through the source code and I spotted what looks to me like a possible bug here:

ipykernel/ipykernel/eventloops.py

Line 455 in d4a8703

close_loop()

This instantiates a coroutine that never gets awaited. Calling an async def function just returns a coroutine object and does not start evaluating the function until the coroutine is started.

Additional poking around makes it look like asyncio loop integration here is actually semi-dead code from an era when the tornado event loop and asynio event loop where not the same event loop (tornado < 5?). Seems like this should be cleaned up, as my read is this old asyncio loop integration is not being maintained. Maybe a deprecation warning should be displayed if anyone tries to use %gui asyncio or something?

[ianthomas23]

@johnfb Thanks for the report. Quite a lot of the event loop code hasn't been updated to correctly use anyio, e.g. #1235. This will need to be done before the 7.0 release.