Can't patch loop of type <class 'NoneType'>

[adriangonz]

After updating to nest_asyncio==1.5.2, it seems that our test suite has started to fail with the following error (the nest_asyncio==1.5.1 release still seems to work fine though):

runtimes/alibi-explain/tests/conftest.py:29: in <module>
    nest_asyncio.apply()
../../.virtualenvs/mlserver-37/lib/python3.7/site-packages/nest_asyncio.py:14: in apply
    raise ValueError('Can\'t patch loop of type %s' % type(loop))
E   ValueError: Can't patch loop of type <class 'NoneType'>

Could this be due to calling nest_asyncio.apply() before an async loop has been created?

[foxik]

We have also been bitten by the same problem -- after installation of Jupyter, jupyter-notebook crashed because loop is None during its startup.

Downgrade to nest_asyncio 1.5.1 solves the problem.

[erdewit]

This is fixed now in v1.5.3

I was trying to replace asyncio.get_event_loop() as it will apparently start to throw an exception in Python 3.11 when the event loop is not running.