I think there a few things still missing in openmpi pmi2 to make it work
with slurm. We are the ones at Bull who integrated the pmi2 code from
mpich2 to slurm. The attached patch should fix the issue (call slurm
with --mpi=pmi2). This still needs to be checked with other pmi2
implemenations (we use pmi2.h but some use pmi.h ? constants are
prefixed with PMI2_ but some use PMI_ ?).