Jeffrey Larson <[email protected]> writes:

I am trying to have a single master, with a group of workers who are themselves calculating function values. The evaluation of the function may itself involve spawning MPI tasks.

How are you running the cpi test then? I ran it with many spawned processes MPI.COMM_SELF.Spawn(cmd, None, 30) and with one spawned process on each of many masters. Neither crashed with current MPICH or Open MPI. What exactly is needed to reproduce the failure you see? I am curious why you want all this process spawning (there are lots of sharp edges to deploying this approach), but mpi4py should work.