anchor.diff:    int exitCode = await process1.exitCode;
     if (exitCode != 0) return process1.exitCode;
   
  +  // Run `pub run build_runner test` and report exit code.
     Process process2 = await Process.start('pub', ['run', 'build_runner', 'test'],
         environment: environment);
     stdout.addStream(process2.stdout);
  
positive.code:   return process2.exitCode;
  }
  
  // Expects to be called with the path to the package root.
  // See .test_config.
  main(List<String> arguments) async {
    String packagePath = arguments[0];
    print("^^^ Run 'annotated_steps.dart' in $packagePath");
    int exitCode = await runBuildRunnerInDirectory(packagePath);
  
negative.code: 
  Uri baseUri = Platform.script.resolve("../../../../../");
  
  /// Run `pub` commands to set up .packages, generate code, and run tests.
  /// Will change current working directory of this process to the root of
  /// the copy of package 'test_reflectable' where the tests are executed.
  int runBuildRunnerInDirectory(String directory) async {
    Map<String, String> environment =
        new Map<String, String>.from(Platform.environment);
    Directory.current = directory;
    print("^^^ Current working directory: ${Directory.current}");
  
    // Run `pub get`, bail out and report exit code if failing.
    Process process1 =
        await Process.start('pub', ['get'], environment: environment);
    stdout.addStream(process1.stdout);
  