anchor.diff:              engineSourcePath = null;
           } on FileSystemException { }
         }
  -      if (engineSourcePath == null) {
  -        String tryEnginePath(String enginePath) {
  -          if (FileSystemEntity.isDirectorySync(path.join(enginePath, 'out')))
  -            return enginePath;
  -          return null;
  -        }
  -        engineSourcePath = tryEnginePath(path.join(ArtifactStore.flutterRoot, '../engine/src'));
  -      }
  +
  +      if (engineSourcePath == null)
  +        engineSourcePath = _tryEnginePath(path.join(ArtifactStore.flutterRoot, '../engine/src'));
  +
         if (engineSourcePath == null) {
           stderr.writeln('Unable to detect local Flutter engine build directory.\n'
               'Either specify a dependency_override for the $kFlutterEnginePackageName package in your pubspec.yaml and\n'
  
positive.code:             'use --engine-src-path to specify the path to the root of your flutter/engine repository.');
          throw new ProcessExit(2);
        }
      }
  
      return engineSourcePath;
  
negative.code:     return 0;
    }
  
    String _tryEnginePath(String enginePath) {
      if (FileSystemEntity.isDirectorySync(path.join(enginePath, 'out')))
        return enginePath;
      return null;
    }
  
    String _findEnginePath(ArgResults globalResults) {
      String engineSourcePath = globalResults['engine-src-path'] ?? Platform.environment[kFlutterEngineEnvironmentVariableName];
      bool isDebug = globalResults['debug'];
  