anchor.diff:  import 'dart:io';
   import 'package:path/path.dart' as path;
   
  -String get cacheDirectory {
  -  final String flutterRepoRoot = path.normalize(path.join(path.dirname(Platform.script.path), '..', '..'));
  -  return path.normalize(path.join(flutterRepoRoot, 'bin', 'cache'));
  -}
  +String get repoRoot => path.normalize(path.join(path.dirname(Platform.script.toFilePath()), '..', '..'));
  +String get cacheDirectory => path.normalize(path.join(repoRoot, 'bin', 'cache'));
   
  +/// Check mime-type of file at [filePath] to determine if it is binary
   bool isBinary(String filePath) {
     final ProcessResult result = Process.runSync(
       'file',
  
positive.code:   return allFiles.where(isBinary).toList();
  }
  
  void main() {
    final List<String> failures = <String>[];
  
    for (final String binaryPath in findBinaryPaths()) {
      print('Verifying the code signature of $binaryPath');
      final ProcessResult result = Process.runSync(
        'codesign',
  
negative.code:   return (result.stdout as String).contains('application/x-mach-binary');
  }
  
  /// Find every binary file in the given [rootDirectory]
  List<String> findBinaryPaths([String rootDirectory]) {
    rootDirectory ??= cacheDirectory;
    final ProcessResult result = Process.runSync(
      'find',
      <String>[
        rootDirectory,
        '-type',
        'f',
        '-perm',
  