anchor.diff:  
   import 'package:json_annotation/json_annotation.dart';
   import 'package:mono_repo/src/package_config.dart';
  +import 'package:mono_repo/src/yaml.dart';
   import 'package:pubspec_parse/pubspec_parse.dart';
   import 'package:test/test.dart';
  -
  -import 'package:mono_repo/src/yaml.dart';
   
   final _dummyPubspec = Pubspec('_example');
   
  
positive.code:       };
        _expectParseThrows(monoYaml, r'''
  line 7, column 7: Stages are not allowed to have the name `test` because it interacts poorly with the default stage by the same name.
        "test": [
        ^^^^^^''');
      });
  
      test('Stages tasks must be a list', () {
  
negative.code:       };
        _expectParseThrows(monoYaml, r'''
  line 7, column 7: Stages are required to have at least one job. "a" is empty.
    ╷
  7 │       "a": []
    │       ^^^
    ╵''');
      });
  
      test('multiple keys under a stage', () {
  