anchor.diff:        if (entity is! Directory) _files.add(entity.path);
       },
           onError: _emitError,
  -        onDone: () {
  -      if (_runningOnBuildbot) {
  -        print("watcher is ready");
  -      }
  -      _readyCompleter.complete();
  -    },
  +        onDone: _readyCompleter.complete,
           cancelOnError: true);
     }
   
  
positive.code:             if (entity is Directory) return;
              _emitEvent(ChangeType.ADD, entity.path);
              _files.add(entity.path);
            }, onError: (e, stackTrace) {
              if (_runningOnBuildbot) {
                print("got error listing $relativePath: $e");
              }
              _emitError(e, stackTrace);
            }, cancelOnError: true);
          } else if (event is FileSystemModifyEvent) {
            assert(!event.isDirectory);
            _emitEvent(ChangeType.MODIFY, path);
  
negative.code:     // probably comes from FSEvents reporting an add that happened prior to the
      // watch beginning.
      if (type == ChangeType.ADD && _files.contains(path)) return;
  
      _eventsController.add(new WatchEvent(type, path));
    }
  