Sorry for the slow reply!
I didn't want to get fixated on why the variable was unset, though I can
understand the existence of a check if Slurm always sets this (I don't
recall that being the case for all configurations historically, but perhaps
it is now). The reason I'd unset it (!) is because I
You might want to take a look at PRRTE (https://github.com/openpmix/prrte) - it
does exactly what you describe., only from the other way around. It provides a
customizable launcher that supports the various cmd lines, and then uses a
common RTE backend.
We don't use SLURM_TASKS_PER_NODE for pla