Since we updated the Mac CI image, we have repeatedly been seeing messages like
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A system call failed during shared memory initialization that should
not have. It is likely that your MPI job will now either abort or
experience performance degradation.
Local host: XXXXXX.local
System call: unlink(2) /var/folders/gf/ddcz224s1czg39z8sns10dhm0000gn/T//ompi.XXXXXX.501/pid.8013/1/vader_segment.XXXXXX.70340001.3
Error: No such file or directory (errno 2)
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(e.g. in https://i10git.cs.fau.de/walberla/walberla/-/jobs/426906). This is a bug in OpenMPI that can be worked around (https://github.com/open-mpi/ompi/issues/5798).