Comment (by Ian Hinder):

Are you sure about that? Those lines belong in an optionlist (mdb/optionlists/*.cfg), not a machine definition file (mdb/machines/*.ini). I would have expected SimFactory to complain if you put those in the machine definition, but maybe it ignores them. In which case, it might just have been doing it again that helped.

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Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2372/fatal-error-in-pmpi_comm_rank-invalid