anchor.diff:          error = 'test failed unexpectedly: $thrownError';
         });
         time.elapse(const Duration(milliseconds: 500));
  -      expect(processMock.lastPubCache, equals('path/to/pub-cache'));
  +      expect(processMock.lastPubCache, equals('custom/pub-cache/path'));
         expect(error, isNull);
       });
     }, overrides: <Type, Generator>{
       ProcessManager: () => new MockProcessManager(69),
       FileSystem: () => new MockFileSystem(),
       Platform: () => new FakePlatform(
  -      environment: <String, String>{'PUB_CACHE': 'path/to/pub-cache'},
  +      environment: <String, String>{'PUB_CACHE': 'custom/pub-cache/path'},
       ),
     });
   }
  
positive.code:     final MockProcessManager processMock = context.getVariable(ProcessManager);
  
      new FakeAsync().run((FakeAsync time) {
        MockDirectory.findCache = false;
        expect(processMock.lastPubEnvironmment, isNull);
        expect(processMock.lastPubCache, isNull);
        pubGet(context: PubContext.flutterTests, checkLastModified: false).then((Null value) {
  
negative.code:     String error;
  
      final MockProcessManager processMock = context.getVariable(ProcessManager);
      final MockFileSystem fsMock = context.getVariable(FileSystem);
  
      new FakeAsync().run((FakeAsync time) {
        MockDirectory.findCache = true;
  