@junghans : If this is going into the main spack repo, we need to better document what it does; but I can't tell what's the best way to do that - any suggestions?

@cferenba Can you write a blurb of documentation for that patch please?

Blurb:
"This patch modifies pfunit to be usable by codes that have MPI_COMM_WORLD hardcoded as their communicator, by skipping over any tests whose PE count does not match the size of the current MPI_COMM_WORLD."

Along with this, I'd recommend renaming the patch to mpi_comm_world.patch, and the variant to something like use-comm-world.

/cc @JohnWGrove