anchor.diff:    final String sparkZip = outputZip == null ? '${DIST_DIR.path}/spark.zip' :
                                                 '${DIST_DIR.path}/${outputZip}';
     _delete(sparkZip);
  -  _deSymlink(joinDir(BUILD_DIR, ['web']), ignoreTop : true);
  +  _removeSymlinks(joinDir(BUILD_DIR, ['web']), ignoreTop : true);
     _zip(context, 'build/web', sparkZip);
     _printSize(context, getFile(sparkZip));
   }
  
positive.code:   BUILD_DIR.createSync();
    DIST_DIR.createSync();
  
    _deSymlink(joinDir(Directory.current, ['web']), ignoreTop : true);
  }
  
  /**
  
negative.code:   return name;
  }
  
  void _removeSymlinks(Directory dir, {bool ignoreTop: false}) {
    for (var entity in dir.listSync(recursive: true, followLinks: false)) {
      if (entity is Link && !ignoreTop) {
        try { entity.deleteSync(); } catch (e) { }
      } else if (entity is Directory) {
        _removeSymlinks(entity);
      }
    }
  }
  