Forward MPI_ROOT to cmake

configure

@@ -120,6 +120,7 @@ with_boost_program_options
 with_boost_iostreams
 with_blas
 with_lapack
+with_mpi
 with_suitesparse
 with_petsc
 with_eigen
@@ -509,6 +510,9 @@ do
       mpivendor)
       conf_options="$conf_options -DMPI_VENDOR=$ac_optarg"
       ;;
+      mpi)
+      conf_options="$conf_options -DMPI_ROOT=$ac_optarg"
+      ;;
       vcdevel)
       conf_options="$conf_options -DVc_ROOT=$ac_optarg"
       ;;

script/set_mpi

@@ -19,7 +19,7 @@ function set_mpi()
         fi
         MPI_installed=1
         export PATH="$1/MPI/bin:$PATH"
-        configure_options="$configure_options --with-mpivendor=openmpi"
+        configure_options="$configure_options --with-mpivendor=openmpi --with-mpi=$1/MPI"
   fi
 
 }