For many years it hasn’t been possible to use pytest-testmon and run tests in parallel via pytest-xdist. With pytest-testmon=>1.4.0 the support has recently been added.
Test parallelization is probably the most general way to speed up a large test suite so this was a major limitation, and I’m glad I was able to lift it. With this addition pytest-testmon will be more relevant for the intended target audience.
We’ve been also able to fix a bug when executing pytest-testmon on Windows. Testmon should work on Windows now, but we’re building more tests to be sure and officially support Windows. Bug reports much appreciated!