API Question: Configure pytest without running it

Hi pytest team,

I am developing the ipytest package, which allows you to run pytest inside the notebook. Recently a question regarding the pytest API came up: is there some API to configure pytest without running it? I browsed the API docs but couldn't find an easy way and just wanted to make sure I did not overlook something. This issue is not breaking and hence resolving it is more a nice to have.

The motivation: a user reported the issue, that pytest.mark.parametrize gives misleading error messages. The root cause for this behavior (see detailed description here) seems to be that the mark generator behaves differently when pytest is configured. For ipytest, the tests are all defined before pytest is run (and configured). Therefore the error message of the mark generator is a little bit tricky to parse.

Start with the pytest API documentation and the configuration lifecycle relevant to pytest.mark.parametrize. Read the linked ipytest issue 39 for the reported behavior, then determine whether a supported configuration-only entry point is needed. Done means a clear API decision and corresponding documentation or implementation scope.