Request stuck in ProcessPoolExecutor about nest_asyncio HOT 4 CLOSED

Requests without DNS lookup inside sync_task do not raise Exceptions in some cases, but I could not find a pattern...

from nest_asyncio.

Removing pool (request in the same thread) fix Exception too, but this is not an option

from nest_asyncio.

Fixed with replacing loop = asyncio.get_event_loop() -> loop = asyncio.new_event_loop() in sync_task and disabling nest_asyncio

Or with asyncio.run(download())

Seems it is bug. The bug is not the first download call exception, the bug is other call success)

from nest_asyncio.

You're using a process pool with forked processes:
https://docs.python.org/3/library/multiprocessing.html#contexts-and-start-methods
This can lead to very weird behaviour, certainly when sockets, threads or event loops are forked over to the new child processes. Spawning the processes (instead of forking) will fix the issue, something like

if __name__ == "__main__":
    mp.set_start_method('spawn')
    pool = ProcessPoolExecutor(max_workers=1)
    main()

from nest_asyncio.