On Wed, Apr 25, 2018 at 2:36 PM, Jed Brown <jed@jedbrown.org> wrote:
It is currently installed to include/petsc/mpiuni/mpi.h and petscsys.h
includes it as <mpi.h>, which means that users of MPIUNI need to put
-I/prefix/include/petsc/mpiuni in their command lines.  Matt and I agree
that this is bad.  We disagree on the solution.

He wants to install it to /prefix/include/mpi.h as though the user had
written --download-mpich.  This would conflict if a user later installs
a real MPI to that location.

The idea should be that "installing" means that everyone is using compatible things
from that location. If you allow an MPIUNI PETSc to be installed to a location that
also has another MPI, what does mpiexec in ./bin do? There is just as much potential
for confusion as there is when putting an MPICH PETSc in a location with OpenMPI
installed.

   Matt
 
I would rather that petscsys.h include <petsc/mpiuni/mpi.h> because it
can't be used without PETSc and nobody who ever wrote #include <mpi.h>
in their own code will be happy if they get MPIUNI.



--
What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
-- Norbert Wiener