I suspect this code is a repro - it certainly locks up the host process reliably enough.

Perhaps if we unblock multiprocessing in the context of a crashed worker then it'll show what the underlying errors are?


import os
from multiprocessing import Pool

def f(x):
    os._exit(0)
    return "success"

if __name__ == '__main__':
    with Pool(1) as p:
        print(p.map(f, [1]))