Please add support to build the openmpi package using alternative compilers such as Intel and Portland in such a way that these packages can be installed together and do not confilct. It would also be great to set a default mpicc, etc using alternatives as well. This would be very helpful for cluster maintainers who use different compilers for different applications.

This functionality is already available (or is now available, at
openmpi 4.1.2)

The under lying C compiler can be set by environment variable OMPI_CC
(more generally OMPI_value, see the man page for mpicc.openmpi).


mpich has the same approach, but no man page. The online manpage at
https://www.mpich.org/static/docs/latest/www1/mpicc.html reports that
there is a --cc command line option to override the C compiler. But
there is also an environment variable MPICH_CC, similar to the openmpi
approach. More fine control can be made through profiles.