MPI_Fortran_COMPILE_OPTIONS, MPI_Fortran_LINK_FLAGS. If "mpi_f08.mod" is not found, typically the MPI include directories are also missing. You can manually check if mpi_f08.mod is preset under the ...
# --with-mpi=yes: Tries to find MPI based on location of mpicc in # $PATH. Configuation fails if MPI can not be found. # --with-mpi=auto: Tries to find MPI based on ...