I have a test to verify an exception is thrown from an async response, which I'm using pytest-asyncio version 0.10.0 to run.

Code is basically:

```
class TestThis:
    @pytest.mark.asyncio
    def test_the_thing(self):
       arg1 = "cmd"
       arg2 = "second command"
       with pytest.raises(CustomException):
           await do_thing(arg1, arg2)

```

Now the really weird thing is this test works fine if I run it alone, or if I run the class alone. However when I run all tests (pytest at the project root), it fails every time with a runtime error, saying the loop is closed.