anchor.diff:  import 'package:args/args.dart';
   import 'package:args/command_runner.dart';
   import 'package:logging/logging.dart';
  +import 'package:path/path.dart' as path;
   
   import '../artifacts.dart';
   import '../build_configuration.dart';
  
positive.code:     argParser.addFlag('debug',
          negatable: false,
          help:
              'Set this if you are building Sky locally and want to use the debug build products. '
              'When set, attempts to automaticaly determine sky-src-path if sky-src-path is '
              'not set. Not normally required.');
      argParser.addFlag('release',
          negatable: false,
          help:
              'Set this if you are building Sky locally and want to use the release build products. '
              'When set, attempts to automaticaly determine sky-src-path if sky-src-path is '
              'not set. Note that release is not compatible with the listen command '
              'on iOS devices and simulators. Not normally required.');
      argParser.addOption('sky-src-path',
          help:
              'Path to your Sky src directory, if you are building Sky locally. '
              'Ignored if neither debug nor release is set. Not normally required.');
      argParser.addOption('android-debug-build-path',
          help:
              'Path to your Android Debug out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/android_Debug/');
      argParser.addOption('android-release-build-path',
          help:
              'Path to your Android Release out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/android_Release/');
      argParser.addOption('ios-debug-build-path',
          help:
              'Path to your iOS Debug out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/ios_Debug/');
      argParser.addOption('ios-release-build-path',
          help:
              'Path to your iOS Release out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/ios_Release/');
      argParser.addOption('ios-sim-debug-build-path',
          help:
              'Path to your iOS Simulator Debug out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/ios_sim_Debug/');
      argParser.addOption('ios-sim-release-build-path',
          help:
              'Path to your iOS Simulator Release out directory, if you are building Sky locally. '
              'This path is relative to sky-src-path. Not normally required.',
          defaultsTo: 'out/ios_sim_Release/');
      argParser.addOption('package-root',
          help: 'Path to your packages directory.', defaultsTo: 'packages');
  
negative.code:   }
  
    List<BuildConfiguration> _createBuildConfigurations(ArgResults globalResults) {
      String enginePath = globalResults['engine-src-path'];
      bool isDebug = globalResults['debug'];
      bool isRelease = globalResults['release'];
  
      if (enginePath == null && globalResults['local-build']) {
        Directory flutterDir = new Directory(path.join(globalResults['package-root'], 'flutter'));
        String realFlutterPath = flutterDir.resolveSymbolicLinksSync();
  
        enginePath = path.dirname(path.dirname(path.dirname(path.dirname(realFlutterPath))));
        if (enginePath == '/' || enginePath.isEmpty)
          enginePath = null;
      }
  
      List<BuildConfiguration> configs = <BuildConfiguration>[];
  
  