anchor.diff:    fail('package $packageName not found in .packages file');
   }
   
  -/// Return the path for `packages/codemirror/codemirror.js`.
  -String _getCodeMirrorScriptPath() {
  -  Map<String, String> packageToUri = {};
  -  for (String line in File('.packages').readAsLinesSync()) {
  -    int index = line.indexOf(':');
  -    packageToUri[line.substring(0, index)] = line.substring(index + 1);
  -  }
  -  String packagePath = Uri.parse(packageToUri['codemirror']).path;
  -  return '${packagePath}codemirror.js';
  -}
  -
   // Run vulcanize
   vulcanize(String filepath) {
  -  FilePath htmlFile = _buildDir.join('web', filepath);
  +  FilePath htmlFile = _buildDir.join(filepath);
     log('${htmlFile.path} original: ${_printSize(htmlFile)}');
     ProcessResult result = Process.runSync(
         'vulcanize',
  
positive.code: @Task('Serve locally on port 8000')
  @Depends(build)
  serve() {
    run('pub', arguments: ['run', 'dhttpd', '-p', '8000', '--path=build/web']);
  }
  
  const String backendVariable = 'DARTPAD_BACKEND';
  
negative.code:   run('sed', arguments: [
      '-i',
      's,https://dart-services.appspot.com,${Platform.environment[backendVariable]},g',
      'build/scripts/main.dart.js',
      'build/scripts/embed.dart.js'
    ]);
    run('pub', arguments: ['run', 'dhttpd', '-p', '8000', '--path=build']);
  }
  
  @Task('Build the `web/index.html` entrypoint')
  build() {
    PubApp.local('build_runner').run(['build', '-r', '-o', 'web:build']);
  
    FilePath mainFile = _buildDir.join('scripts/main.dart.js');
    log('${mainFile} compiled to ${_printSize(mainFile)}');
  
    FilePath testFile = _buildDir.join('test', 'web.dart.js');
    if (testFile.exists)
      log('${testFile.path} compiled to ${_printSize(testFile)}');
  
    FilePath embedFile = _buildDir.join('scripts/embed.dart.js');
    log('${mainFile} compiled to ${_printSize(embedFile)}');
  
    // Remove .dart files.
    int count = 0;
  
    for (FileSystemEntity entity in getDir('build/packages')
        .listSync(recursive: true, followLinks: false)) {
      if (entity is! File) continue;
      if (!entity.path.endsWith('.dart')) continue;
  