MPI_Comm_spawn fails with OpenMPI

[cbenazet]

Hi,

I'm trying to use pytest_parallel with slurm with OpenMPI, but I get this error message:

PSM2 returned unhandled/unknown connect error: Error in a function parameter
OPAL ERROR: Error in file dpm/dpm.c at line 495
PSM2 returned unhandled/unknown connect error: Error in a function parameter
OPAL ERROR: Error in file dpm/dpm.c at line 495
*** An error occurred in MPI_Init_thread
*** reported by process [1583349762,0]
*** on a NULL communicator
*** Unknown error
*** MPI_ERRORS_ARE_FATAL (processes in this communicator will now abort,
***    and MPI will try to terminate your MPI job as well)

in a call at pytest_parallel/utils/mpi.py:spawn_master_process