anchor.diff:          enableLowResourcesMode: options.enableLowResourcesMode,
           assumeTty: options.assumeTty,
           outputDir: outputDir,
  -        verbose: options.verbose);
  +        verbose: options.verbose,
  +        packageGraph: packageGraph);
   
       // Run the tests!
       await _runTests(outputDir);
  
positive.code: 
    @override
    Future<Null> run() async {
      var options = _readOptions();
      // We always need an output dir when running tests, so we create a tmp dir
      // if the user didn't specify one.
  
negative.code:     }
    }
  }
  
  void _ensureBuildTestDependency(PackageGraph packageGraph) {
    if (packageGraph.allPackages['build_test'] == null) {
      throw new StateError('''
  Missing dev dependecy on package:build_test, which is required to run tests.
  
  Please update your dev_dependencies section of your pubspec.yaml:
  
    dev_dependencies:
      build_runner: any
      build_test: any
      # If you need to run web tests, you will also need this dependency.
      build_web_compilers: any
  ''');
    }
  }
  