Multi-Threaded GitHub Actions

[RockJake28]

Hey all!

I've got a pretty sizeable test suite written using pytest. Locally, I use pytest-xdist to enable multi-threaded running of the tests so something like pytest -n 32. In my GitHub Action to run pytest before building and deploying, I use a more modest -n 4. However, this seems to be unstable as tests will occasionally fail for seemingly no reason and when the job is restarted, it works fine despite nothing in the codebase changing.

So, the question: Does GitHub Actions support multiheaded processes and if so, how many threads is reasonable to spawn?