Websocket hangs with Windows and Python 3.8

[jyu00]

Connection via websockets hangs when running on Windows with Python 3.8, nest_asyncio, and the default WindowsProactorEventLoopPolicy. A simple program can reproduce this:

import asyncio
import nest_asyncio
from websockets import connect

nest_asyncio.apply()

async def _connect():
    websocket = await connect('wss://wss.foo.com:9876')

def client():
    loop = asyncio.get_event_loop()
    return loop.run_until_complete(_connect())

if __name__ == "__main__":
    client()

This works on other platforms/Python versions/policy, or without nest_asyncio. I did a little bit of tracing, and it looks like the connect() completed successfully, but it somehow got stuck when selecting the next event.

[erdewit]

In the script to reproduce the issue it seems that the definition for job_status is omitted.

[jyu00]

Yeah sorry the simplified version should not have job_status. Updated the original text.

[WestXu]

pip install nest_asyncio==1.3.3 fixes it.

[erdewit]

I can reproduce the issue on Windows 10, Python 3.9. The issue is the ProactorEvenLloop getting a timeout of None in a select call, which then leaves it hanging. A work-around has been added to use a definite timeout value instead of None.

[erdewit]

This is released now in v1.4.2.