anchor.diff:          Uri rootUri = flutterUri.resolve('../../..');
           String flutterPath = path.normalize(new File.fromUri(rootUri).absolute.path);
   
  -        if (flutterPath != Cache.flutterRoot) {
  -          // Warn and exit the app.
  +        if (!_compareResolvedPaths(flutterPath, Cache.flutterRoot)) {
             printError(
  -            'Warning - the active Flutter is different from the one referenced in your pubspec:\n'
  -            '  active Flutter   : ${Cache.flutterRoot}\n'
  -            '  pubspec reference: $flutterPath'
  +            'Warning: the \'flutter\' tool you are currently running is different from the one referenced in your pubspec.yaml:\n'
  +            '  running Flutter  : ${Cache.flutterRoot}\n'
  +            '  pubspec reference: $flutterPath\n'
  +            'This can happen when you have multiple copies of flutter installed. Please check your system path to verify\n'
  +            'that you\'re running the expected version (run \'flutter --version\' to see which flutter is on your path). You\n'
  +            'can also change which flutter your project points to by editing the \'flutter:\' path in your pubspec.yaml file.\n'
             );
  -          return false;
           }
         }
       }
  
positive.code:       FileSystemEntity.isFileSync(path.join(directory, 'bin/cache/engine.stamp'));
    }
  }
  
negative.code:     // Check if the cwd is a flutter dir.
      while (directory.isNotEmpty) {
        if (_isDirectoryFlutterRepo(directory)) {
          if (!_compareResolvedPaths(directory, Cache.flutterRoot)) {
            printError(
              'Warning: the \'flutter\' tool you are currently running is not the one from the current directory:\n'
              '  running Flutter  : ${Cache.flutterRoot}\n'
              '  current directory: $directory\n'
              'This can happen when you have multiple copies of flutter installed. Please check your system path to verify\n'
              'that you\'re running the expected version (run \'flutter --version\' to see which flutter is on your path).\n'
            );
          }
  
  