anchor.diff:    IsolateLoaderState(this.isolateId);
   
     final int isolateId;
  -
  +  bool _dead = false;
     SendPort sp;
   
     void init(String packageRootFlag, String packagesConfigFlag,
         String workingDirectory, String rootScript) {
  +    if (_dead) {
  +      return;
  +    }
       // _workingDirectory must be set first.
       _workingDirectory = new Uri.directory(workingDirectory);
       if (rootScript != null) {
  
positive.code:   RawReceivePort _packagesPort;
  
    void _requestPackagesMap([Uri packageConfig]) {
      assert(_packagesPort == null);
      assert(_rootScript != null);
      // Create a port to receive the packages map on.
      _packagesPort = new RawReceivePort(_handlePackagesReply);
      var sp = _packagesPort.sendPort;
  
negative.code:     if (packagesConfigFlag != null) {
        _setPackagesConfig(packagesConfigFlag);
      }
      if (_fileRequestQueue != null) {
        _fileRequestQueue = new List<FileRequest>();
      }
    }
  
    void cleanup() {
      _dead = true;
      if (_packagesPort != null) {
        _packagesPort.close();
        _packagesPort = null;
  