mpiexec hangs with multiprocessing with a non-fork start method #501

import multiprocessing

from mpi4py import MPI

def test_pool():
    multiprocessing.set_start_method("spawn")
    with multiprocessing.Pool(2) as pool:
        pool.apply(f, ())

def f():
    pass

if __name__ == "__main__":
    test_pool()