Hi MPICH-developers, I’ve built MPICH-3.3.2 from source on my univ. cluster to ensure that jobs can be launched with slurm’s srun (via —mpi=pmi2, slurm’s native pmi version). I built mpich from source using spack using ch4:ucx. I see the following errors in my outfile (from osu-micro-benchmarks runs): .... slurmstepd: error: mpi/pmi2: no value for key in req .... [1574612953.443924] [qnode5038:30333:0] mpool.c:38 UCX WARN object 0x1b88d00 was not returned to mpool ucp_rkeys ... ` as shown in a typical outfile here. I don’t see such errors with using openmpi-4.0.2 which was also built with UCX as the primary transport layer protocol where I compiled a newer version of UCX from source. I’m attaching the build log from mpich install for reference. Windows Terminal[sas4990@quser10 ~]$ spack find -ldv mpich%[email protected] ==> 1 installed package -- linux-rhel7-ivybridge / [email protected] ---------------------------- btlyk64 [email protected] device=ch4 +hydra netmod=ucx +pci pmi=pmi2 +romio+slurm~verbs+wrapperrpath eb74crw [email protected] t6h6tgg [email protected]~python 46i2h6v [email protected] dnbfmo2 [email protected] xaq5v23 [email protected]+optimize+pic+shared 77kx7yy slurm@19-05-3-2~gtk~hdf5~hwloc~mariadb~pmix+readline [sas4990@quser10 ~]$ Thanks in advance for your help! -- Sajid Ali | PhD Candidate Applied Physics Northwestern University s-sajid-ali.github.io