anchor.diff:      final int code = await runCommandAndStreamOutput(args,
         workingDirectory: directory,
         mapFunction: _filterOverrideWarnings,
  -      environment: <String, String>{ 'FLUTTER_ROOT': Cache.flutterRoot }
  +      environment: <String, String>{ 'FLUTTER_ROOT': Cache.flutterRoot, _pubEnvironmentKey: _getPubEnvironmentValue() }
       );
       status.stop();
       if (code != 0)
  
positive.code: 
  final RegExp _analyzerWarning = new RegExp(r'^! \w+ [^ ]+ from path \.\./\.\./bin/cache/dart-sdk/lib/\w+$');
  
  String _filterOverrideWarnings(String message) {
    // This function filters out these three messages:
    //   Warning: You are using these overridden dependencies:
  
negative.code: import '../base/common.dart';
  import '../base/file_system.dart';
  import '../base/logger.dart';
  import '../base/platform.dart';
  import '../base/process.dart';
  import '../base/utils.dart';
  import '../cache.dart';
  import '../globals.dart';
  import 'sdk.dart';
  