CI: No single CPU builds for pytest.mark.single test?

[mroeschke]

The single mark is supposed to be for mark a test as single cpu only

If I am interpreting the purpose correctly, these tests should be run with pytest -n 1. Though in our CI, I see PYTEST_WORKERS as either "auto" or 2

Github actions runners seem multi core: https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners#supported-runners-and-hardware-resources
Same with azure runners: https://docs.microsoft.com/en-us/azure/devops/pipelines/agents/hosted?view=azure-devops&tabs=yaml#hardware

So is it correct that we aren't running these single tests as intended?

cc @lithomas1

[lithomas1]

This is not that hard to do. I think we can add "not single" to the -k argument when running the tests and then run pytest -k "single" -n 1 or something afterwards.

I don't understand why these are single core only though and I'm pretty sure the tests are actually still being run in the regular CI.

[mroeschke]

Right, I think these tests are still being run, but maybe the intention is that @pytest.mark.single tests should be run on a single core to avoid flakiness when running with multiple cores?

[mroeschke]

This was fixed

[jbrockmendel]

There are a couple of # TODO(GH#44584): Mark these as pytest.mark.single_cpu in the code. since this is closed, can these be addressed?

[mroeschke]

Yeah I bet those tests can be marked as single_cpu now