Arch Linux

Description: openmpi 4.1.5 won't spawn with OpenPMIx v4.2.3. The patch [openmpi-4.1.5-openpmix_4.2.3.patch](https://gitlab.archlinux.org/archlinux/packaging/packages/openmpi/-/blob/main/openmpi-4.1.5-openpmix_4.2.3.patch) breaks spawn.


Additional info:
* package version(s): openmpi-4.1.5-2
* link to upstream bug report: https://github.com/open-mpi/ompi/issues/11749
* A working patch: https://github.com/open-mpi/ompi/issues/11749#issuecomment-1591599763

Steps to reproduce:
An MWE (copied from upstream) built with `gcc main.c -lmpi` and run by `./a.out`
```c
#include <stdio.h>
#include <mpi.h>

int main(int argc, char* argv[])
{
MPI_Init(NULL, NULL);

MPI_Comm comm;
MPI_Comm parent, child;
MPI_Comm_get_parent(&parent);
if (parent == MPI_COMM_NULL) {
int errors[3];
MPI_Comm_spawn(argv[0], NULL, 3, MPI_INFO_NULL, 0,
MPI_COMM_WORLD, &child, errors);
MPI_Intercomm_merge(child, 0, &comm);
MPI_Comm_free(&child);
} else {
MPI_Intercomm_merge(parent, 1, &comm);
}

int rank;
MPI_Comm_rank(comm, &rank);
printf("Hello, I am rank %d in the merged comm\n", rank);
MPI_Barrier(comm);
MPI_Comm_free(&comm);

MPI_Finalize();
return 0;
}
```
Desired output (the order does not matter):
```
Hello, I am rank 0 in the merged comm
Hello, I am rank 3 in the merged comm
Hello, I am rank 1 in the merged comm
Hello, I am rank 2 in the merged comm
```