@stinner your traceback suggestion was highly useful and much appreciated. i have spent several dozen hours researching ResourceWarnings in the past and tearing my hair out because the emitted warning was very much useless. i couldn't even make educated guesses about the code as socket pairs were used randomly.

i strongly approve of mentioning the tracemalloc / traceback in the warning, and i would also very much encourage saying "this filename:position could be completely wrong" or do away with it all together.