message: Verbose output for -sg failure
diff: @@ -554,7 +554,7 @@ usage --> "--generate:type[:parameter1=value,parameter2=value,...]"
  }
  if (children.empty()) {
  - std::cerr << "Warning: no children found in -sg: lookup\n";
  + std::cerr << "Warning: no children found for " << av[i] << " lookup\n";
  continue;
  }
  