message: Fix the conduit data collection: the member 'field_map' is not an
  std::map anymore, so it does not support the array subscript operator.
diff: @@ -1089,7 +1089,7 @@ ConduitDataCollection::LoadMeshAndFields(int domain_id,
  )
  {
  GridFunction *gf = BlueprintFieldToGridFunction(mesh, n_field);
  - field_map[field_name] = gf;
  + field_map.Register(field_name, gf, true);
  }
  }
  }
  