anchor.diff:      Pub: () => const Pub(),
     });
   
  -  test('Pub error handling', () {
  +  test('Pub error handling', () async {
       final MemoryFileSystem fileSystem = MemoryFileSystem();
       final FakeProcessManager processManager = FakeProcessManager.list(<FakeCommand>[
         FakeCommand(
  
positive.code:             ..setLastModifiedSync(DateTime(2002));
          }
        ),
      ]);
      Testbed().run(() async {
        // the good scenario: .packages is old, pub updates the file.
        fs.file('.packages')
          ..createSync()
  
negative.code:         ..setLastModifiedSync(DateTime(9999));
        assert(DateTime(9999).isAfter(DateTime.now()));
        await pub.get(context: PubContext.flutterTests, checkLastModified: true); // pub does nothing
        expect(testLogger.statusText, contains('Running "flutter pub get" in /...\n'));
        expect(testLogger.errorText, startsWith(
          'Warning: File "/pubspec.yaml" was created in the future. Optimizations that rely on '
          'comparing time stamps will be unreliable. Check your system clock for accuracy.\n'
          'The timestamp was:'
        ));
        testLogger.clear();
      }, overrides: <Type, Generator>{
  