Github actions runner times out in seemingly random cases

I have encountered a rather difficult to debug issue using github actions for one of my python projects. From time to time one of the github actions runners is so slow that it gets killed after the timeout of 6h. Other similar runners finish in a few minutes, and the same runner may be just fine when re-running the jobs.

One example for this can be found here where the noexif environment timed out or here where it was the piexif one.

The action uses pytest within tox to test a PyQt5 application. I have not had any performance issues locally and with the underlying randomness, i.e. some runner failing once but not repeatedly, I am unsure how to proceed.

Any help on how to debug this would be appreciated a lot! Let me know if there is further information I should add. Thanks in advance :blush: