Gilles Gouaillardet

There is an issue in `VPATH` mode, and here is a possible fix (probably worth rewriting for style...) ``` diff --git a/ompi/mpi/c/Makefile.am b/ompi/mpi/c/Makefile.am index b50fa7d1f9..f665b8bbbd 100644 --- a/ompi/mpi/c/Makefile.am +++ b/ompi/mpi/c/Makefile.am...

@bwbarrett (one) CI failure was caused because `python 3.8` is now a requirement and is not installed on an EC2 instance. Could you please take care of that?

As far as I understand, the SLURM sets the `PMIX_APPNUM` key and Open MPI retrieves it in order to set the `MPI_APPNUM` attribute. **that being said** SLURM always sets `PMIX_APPNUM`...

Which version of Open MPI are you running? This is a bug if the `MPI_APPNUM` attribute of `MPI_COMM_WORLD` is **not** set. I was unable to reproduce this issue: the attribute...

@b-fg when using `srun`, do you use PMI-1, PMI-2 or PMIx?

@bosilca, this is a snippet from the SLURM PMIx plugin from `src/plugins/mpi/pmix/pmixp_client.c`: ``` /* TODO: always use 0 for now. This is not the general case * though (see Slurm...

FWIW, MPICH and Open MPI behave the same: `MPI_APPNUM` is defined and always `0` when `srun` is used. (in both cases, this is incorrect when MPMD is used) Currently, `mpirun...

This question was initially asked on Stack Overflow at https://stackoverflow.com/questions/58196889/mpi-program-behaves-differently-on-linux Note Ubuntu 18.04 is shipping Open MPI 2.1.1 and not the latest 4.0.1. You can also try an other MPI...

Please do not misinterpret my previous comments. I am not stating your conclusion (e.g. there is a bug in Open MPI) is incorrect (you have not shared a way to...

@asanchez500 it seems you are not running under a resource manager (such as Slurm, PBSPro and others). In this case, a requirement is you must be able to ssh passwordless...