anchor.diff:        deleteEntity(entity);
       }
     }
  +
  +  _deSymlink(joinDir(BUILD_DIR, ['web']), ignoreTop : true);
   }
   
   Future releaseNightly(GrinderContext context) {
  
positive.code:   // It needs to be copied to compile result directory.
    copyFile(
        joinFile(Directory.current, ['web', 'manifest.json']),
        joinDir(BUILD_DIR, ['deploy-out', 'web']));
  
    return version;
  }
  
negative.code:   }
  
    return name;
  }
  
  void _deSymlink(Directory dir, {bool ignoreTop: false}) {
    for (FileSystemEntity entity in dir.listSync(recursive: true, followLinks: false)) {
      if (entity is Link && !ignoreTop) {
        try { entity.deleteSync(); } catch (e) { }
      } else if (entity is Directory) {
        _deSymlink(entity);
      }
    }
  }
  
  /**
  