anchor.diff:        args.add('--preview-dart-2');
         args.addAll(_replaceDartFiles(arguments, tempKernelFile(tempDir)));
       } else {
  +      args.add('--no-preview-dart-2');
         args.addAll(arguments);
       }
   
  
positive.code:         args.add('--no-background-compilation');
        }
      } else {
        if (_isStrong) {
          args.add('--strong');
        }
  
negative.code:     }
      if (useDfe) {
        args.add('--preview-dart-2');
      } else {
        args.add("--no-preview-dart-2");
      }
      args
        ..addAll(vmOptions)
  