anchor.diff:    String computeCompilerPath() {
       var dir = _useSdk
           ? "${_configuration.buildDirectory}/dart-sdk"
  +        // TODO(38701): Cleanup after merging the forked SDK into mainline.
           : _configuration.nnbdMode == NnbdMode.legacy ? "sdk" : "sdk_nnbd";
       return "$dir/bin/dartdevc$shellScriptExtension";
     }
  
positive.code:       CommandArtifact artifact) {
      var sdk = _useSdk
          ? Uri.directory(_configuration.buildDirectory).resolve('dart-sdk/')
          : Uri.directory(Repository.dir.toNativePath()).resolve('sdk/');
      var preambleDir = sdk.resolve('lib/_internal/js_runtime/lib/preambles/');
      return runtimeConfiguration.dart2jsPreambles(preambleDir)
        ..add(artifact.filename);
  
negative.code:       : super._subclass(configuration);
  
    String computeCompilerPath() {
      var prefix =
          // TODO(38701): Cleanup after merging the forked SDK into mainline.
          _configuration.nnbdMode == NnbdMode.legacy ? 'sdk/bin' : 'sdk_nnbd/bin';
      var suffix = shellScriptExtension;
  
      if (_isHostChecked) {
  