Spack & MPI

TODO: introduce how to link libfabrics, etc. properly to compose an environment with the vendor provided MPI

• How to build MPICH in Spack that can still communicate through the Cray’s interconnect:

libfabric:
    buildable: false
    externals:
    - spec: [email protected] fabrics=cxi
    prefix: /opt/cray/libfabric/2.3.1

TODO: Cray’s MPI

The key is to at minimum include libfabric as non-buildable dependencies. This is still inferior than also including both cray-pmi and cray-mpich as non-buildable.