How to use [fix](https://github.com/aio-libs/aiopg/issues/678#issuecomment-667908402) with pytest.

[heckad]

I tried to add this to conftest and this didn't solve problem. Pytest still uses ProactorEventLoop.

[RonnyPfannschmidt]

this is a issue with pytest-asyncio - as far as i understood you need to set up its event loop replacement policy (it uses separate event loops)

see its documentation

[heckad]

We don't use pytest-asyncio only pytest and aiopg under windows. Ower tests fails with NotImplementedError because pytest used ProactorEventLoop instead SelectorEventLoop. How to change event loop?

[RonnyPfannschmidt]

pytest itself does not configure the event loop, i suspect that by the time your conftest is imported, a event loop was acquired somewhere
if you use asyncio, i strongly recommend using a pytest-plugin that configures it for testing

[heckad]

I just need to use loop fixture to set the desired event loop. Problem solved.