[Bug]: CHPL_LAUNCHER=mpirun4ofi does not work on MacOS with mpirun (Open MPI) 5.0.6

[jabraham17]

Summary of Problem

I tried to test the OFI comm layer by running oversubscribed on my Mac and ran into some issues with the launcher.

I set the following env vars, then tried to run hello world

  export CHPL_COMM=ofi
  export CHPL_COMM_OFI_OOB=mpi
  export CHPL_LAUNCHER=mpirun4ofi
  export MPI_DIR=/opt/homebrew/opt/open-mpi/
  export CHPL_RT_OVERSUBSCRIBED=yes

This errors out with the following message

./a.out -nl 1 -v
FI_SOCKETS_PE_WAITTIME=0 HUGETLB_MORECORE=no mpirun -np 1 -map-by ppr:1:node -map-by node:oversubscribe -bind-to none -mca mpi_yield_when_idle 1 a.out_real -nl 1 -v
--------------------------------------------------------------------------
ERROR: The "map-by" command line option was listed more than once on the command line.
Only one instance of this option is permitted.
Please correct your command line.
--------------------------------------------------------------------------

I was able to work around this by manually launching the _real executable as

NUMLOCALES=1
FI_SOCKETS_PE_WAITTIME=0 HUGETLB_MORECORE=no mpirun -map-by ppr:$NUMLOCALES:node:oversubscribe -bind-to none -mca mpi_yield_when_idle 1 a.out_real -nl $NUMLOCALES -v

I think we can adjust the mpirun4ofi to use this sequence of commands to make it work for open-mpi on Mac, but I don't know what effect that would have on other platforms (or other versions of mpi).

Configuration Information

• Output of chpl --version: 2.4 pre release
• Output of $CHPL_HOME/util/printchplenv --anonymize:

CHPL_TARGET_PLATFORM: darwin
CHPL_TARGET_COMPILER: llvm
CHPL_TARGET_ARCH: arm64
CHPL_TARGET_CPU: native *
CHPL_LOCALE_MODEL: flat
CHPL_COMM: ofi *
  CHPL_LIBFABRIC: bundled
  CHPL_COMM_OFI_OOB: mpi *
CHPL_TASKS: qthreads
CHPL_LAUNCHER: mpirun4ofi *
CHPL_TIMERS: generic
CHPL_UNWIND: none
CHPL_TARGET_MEM: jemalloc *
CHPL_ATOMICS: cstdlib
  CHPL_NETWORK_ATOMICS: ofi
CHPL_GMP: system *
CHPL_HWLOC: system *
CHPL_RE2: bundled *
CHPL_LLVM: system
CHPL_AUX_FILESYS: none

• Back-end compiler and version, e.g. gcc --version or clang --version: LLVM 19, clang 14