message: fixed build error after commit
diff: @@ -41,8 +41,8 @@ struct mpi_sub_comm {
  if (nb_procs>mpi_world_nb_procs()) {
  if (comm_world_rank==0) {
  MESSAGE(
  - "Unable to run test: need "+std::to_string(nb_procs) + " procs"
  - + " but program launched with only "+std::to_string(doctest::mpi_world_nb_procs()) + "."
  + "Unable to run test: need ", std::to_string(nb_procs), " procs",
  + " but program launched with only ", std::to_string(doctest::mpi_world_nb_procs()), "."
  );
  CHECK(nb_procs<=mpi_world_nb_procs());
  }
  