Singleton Init and `MPI_Session_get_num_psets()`

[dalcinl]

trafficstars

Configuration

./configure --prefix=/home/devel/mpi/openmpi/dev --without-ofi --without-ucx --with-pmix=internal --with-prrte=internal --with-libevent=internal --with-hwloc=internal --enable-debug --enable-mem-debug --disable-man-pages --disable-sphinx

Reproducer

• Python code:

from mpi4py import MPI

session = MPI.Session.Init()
num = session.Get_num_psets()
session.Finalize()

• Execution (singleton init, without mpiexec):

python script.py

Behavior

Deadlock at the num = session.Get_num_psets() line.

[dalcinl]

@hppritcha You may want to take a look at this one.

[hppritcha]

closed via #10885 and #10891