anchor.diff:    try {
       final String version = runCheckedSync(<String>['xcodebuild', '-version']);
       final Match match = _xcodeVersionRegExp.firstMatch(version);
  -    if (int.parse(match[1]) < 7) {
  +    if (int.parse(match[1]) < kXcodeRequiredVersionMajor) {
         printError('Found "${match[0]}". $_xcodeRequirement');
         return false;
       }
  
positive.code:   }
    if (result.xcodeBuildExecution != null &&
        result.xcodeBuildExecution.buildForPhysicalDevice &&
        // Make sure the user has specified at least the DEVELOPMENT_TEAM (for automatic Xcode 8)
        // signing or the PROVISIONING_PROFILE (for manual signing or Xcode 7).
        !(app.buildSettings?.containsKey('DEVELOPMENT_TEAM')) == true || app.buildSettings?.containsKey('PROVISIONING_PROFILE') == true) {
      printError(noDevelopmentTeamInstruction, emphasis: true);
      return;
  
negative.code: }
  
  final RegExp _xcodeVersionRegExp = new RegExp(r'Xcode (\d+)\..*');
  final String _xcodeRequirement = 'Xcode $kXcodeRequiredVersionMajor.$kXcodeRequiredVersionMinor or greater is required to develop for iOS.';
  
  bool _checkXcodeVersion() {
    if (!platform.isMacOS)
  