message: Error message if user runs gslib serial example with parallel build
diff: @@ -42,6 +42,9 @@ int main (int argc, char *argv[])
  return 1;
  }
  args.PrintOptions(cout);
  +#ifdef MFEM_USE_MPI
  + MFEM_ABORT("Serial example is not compatible with parallel build.");
  +#endif
  // Initialize and refine the starting mesh.
  Mesh mesh(mesh_file, 1, 1, false);
  