anchor.diff:    String get name => bundleName;
   
     @override
  -  String applicationBundle(BuildMode buildMode) => bundleDir.path;
  +  String? applicationBundle(BuildMode buildMode) => bundleDir.path;
   
     @override
  -  String executable(BuildMode buildMode) => _executable;
  +  String? executable(BuildMode buildMode) => _executable;
   }
   
   class BuildableMacOSApp extends MacOSApp {
  
positive.code:   @override
    String get displayName => id;
  
    String applicationBundle(BuildMode buildMode);
  
    String executable(BuildMode buildMode);
  }
  
  class PrebuiltMacOSApp extends MacOSApp {
    PrebuiltMacOSApp({
      @required this.bundleDir,
      @required this.bundleName,
      @required this.projectBundleId,
      @required String executable,
    }) : _executable = executable,
         super(projectBundleId: projectBundleId);
  
  
negative.code:   String get name => 'macOS';
  
    @override
    String? applicationBundle(BuildMode buildMode) {
      final File appBundleNameFile = project.nameFile;
      if (!appBundleNameFile.existsSync()) {
        globals.printError('Unable to find app name. ${appBundleNameFile.path} does not exist');
  