anchor.diff:  void main(List<String> arguments) {
     assert(arguments.length == 1);
     final String outPath = arguments.first;
  +  String platform;
  +  if (Platform.isLinux) {
  +    platform = 'linux-x64';
  +  } else if (Platform.isMacOS) {
  +    platform = 'mac-x64';
  +  } else {
  +    throw new UnimplementedError('Script only support running on Linux or MacOS.');
  +  }
  +  final String nmPath = p.join(p.dirname(outPath), 'buildtools', platform, 'clang', 'bin', 'llvm-nm');
     assert(new Directory(outPath).existsSync());
   
     final Iterable<String> releaseBuilds = new Directory(outPath).listSync()
  
positive.code:       .where((String s) => s.startsWith('android_'));
  
    int failures = 0;
    failures += _checkIos(outPath, iosReleaseBuilds);
    failures += _checkAndroid(outPath, androidReleaseBuilds);
  
    exit(failures);
  }
  
  int _checkIos(String outPath, Iterable<String> builds) {
    int failures = 0;
    for (String build in builds) {
      final String libFlutter = p.join(outPath, build, 'Flutter.framework', 'Flutter');
      final String stdout = Process.runSync('nm', <String>['-gUm', libFlutter]).stdout;
      print('+++ DEBUG: stdout of nm +++');
      print(stdout);
      print('+++ END: stdout of nm +++');
  
negative.code:   return failures;
  }
  
  int _checkAndroid(String outPath, String nmPath, Iterable<String> builds) {
    int failures = 0;
    for (String build in builds) {
      final String libFlutter = p.join(outPath, build, 'libflutter.so');
      final String stdout = Process.runSync(nmPath, <String>['-gU', libFlutter]).stdout;
      print('+++ DEBUG: stdout of nm +++');
      print(stdout);
      print('+++ END: stdout of nm +++');
  