anchor.diff:          help: 'Path to your packages directory.', defaultsTo: 'packages');
     }
   
  -  List<BuildConfiguration> buildConfigurations;
  +  List<BuildConfiguration> get buildConfigurations {
  +    if (_buildConfigurations == null)
  +      _buildConfigurations = _createBuildConfigurations(_globalResults);
  +    return _buildConfigurations;
  +  }
  +  List<BuildConfiguration> _buildConfigurations;
  +
  +  ArgResults _globalResults;
   
     Future<int> runCommand(ArgResults globalResults) async {
       if (globalResults['verbose'])
  
positive.code:           message += '\nDid you run this command from the same directory as your pubspec.yaml file?';
        }
        _logging.severe(message);
        return 2;
      }
  
      buildConfigurations = _createBuildConfigurations(globalResults);
  
      return super.runCommand(globalResults);
    }
  
    List<BuildConfiguration> _createBuildConfigurations(ArgResults globalResults) {
      String enginePath = globalResults['engine-src-path'];
      bool isDebug = globalResults['debug'];
      bool isRelease = globalResults['release'];
  
negative.code:     if (globalResults['very-verbose'])
        Logger.root.level = Level.FINE;
  
      _globalResults = globalResults;
      return super.runCommand(globalResults);
    }
  
    List<BuildConfiguration> _createBuildConfigurations(ArgResults globalResults) {
      ArtifactStore.packageRoot = globalResults['package-root'];
      if (!FileSystemEntity.isDirectorySync(ArtifactStore.packageRoot)) {
        String message = '${ArtifactStore.packageRoot} is not a valid directory.';
  