The code in test.py is not realistic. It spawns children only to terminate them straight away, and you could easily reap each child after calling terminate(). You might have more influence with a realistic use case.

Victor has committed a fix for the “exception ignored” problem, so assuming it works, in the next release of Python it should be gone. You should still see a ResourceWarning if warnings are enabled, but I don’t think -Wignore would be necessary to suppress them; such warnings are disabled by default.