anchor.diff:      Callback setUpFunction}) async {
     args = args.toList();
     bool verbose = args.remove('-v');
  +
  +  var relativeDir = dataDir.uri.path.replaceAll(Uri.base.path, '');
  +  print('Data dir: ${relativeDir}');
     await for (FileSystemEntity entity in dataDir.list()) {
       String name = entity.uri.pathSegments.last;
       if (args.isNotEmpty && !args.contains(name)) continue;
  
positive.code:     };
  
      if (libDirectory != null) {
        print('----------------------------------------------------------------');
        print('Loading support libraries:');
        String filePrefix = name.substring(0, name.lastIndexOf('.'));
        await for (FileSystemEntity libEntity in libDirectory.list()) {
          String libFileName = libEntity.uri.pathSegments.last;
          if (libFileName.startsWith(filePrefix)) {
            print('    - loading ${libEntity.uri}');
            Uri libFileUri =
                Uri.parse('memory:$commonTestPath/libs/$libFileName');
            userFiles.add(libEntity.uri.pathSegments.last);
  
negative.code:       testOptions.add(Flags.enableAsserts);
      }
      print('----------------------------------------------------------------');
      print('Test: $name');
      // Pretend this is a dart2js_native test to allow use of 'native' keyword
      // and import of private libraries.
      String commonTestPath = 'sdk/tests/compiler';
  