anchor.diff:  
     bool _upIsDown;
   
  -  bool get saneAsyncStacks => _saneAsyncStacks;
  -  void set saneAsyncStacks(bool value) {
  +  bool get causalAsyncStacks => _causalAsyncStacks;
  +  void set causalAsyncStacks(bool value) {
       settings.set('causal-async-stacks', value);
  -    _saneAsyncStacks = value;
  -  }
  -
  -  bool _saneAsyncStacks;
  -
  +    _causalAsyncStacks = value;
  +  }
  +
  +  bool _causalAsyncStacks;
  +
  +  bool get awaiterStacks => _awaiterStacks;
  +  void set awaiterStacks(bool value) {
  +    settings.set('awaiter-stacks', value);
  +    _causalAsyncStacks = value;
  +  }
  +
  +  bool _awaiterStacks;
  +
  +  static const String kAwaiterStackFrames = 'awaiterFrames';
     static const String kAsyncCausalStackFrames = 'asyncCausalFrames';
     static const String kStackFrames = 'frames';
   
  
positive.code:     ],
      'causal-async-stacks': [
        _boolValues,
        _setSaneAsyncStacks,
        (debugger, _) => debugger.saneAsyncStacks
      ],
    };
  
    static Future _setBreakOnException(debugger, name, value) async {
  
negative.code:   }
  
    int get stackDepth {
      if (awaiterStacks) {
        var awaiterStackFrames = stack[kAwaiterStackFrames];
        if (awaiterStackFrames != null) {
          return awaiterStackFrames.length;
        }
      }
      if (causalAsyncStacks) {
        var asyncCausalStackFrames = stack[kAsyncCausalStackFrames];
        if (asyncCausalStackFrames != null) {
          return asyncCausalStackFrames.length;
        }
      }
      return stack[kStackFrames].length;
    }
  
    List get stackFrames {
      if (awaiterStacks) {
        var awaiterStackFrames = stack[kAwaiterStackFrames];
        if (awaiterStackFrames != null) {
          return awaiterStackFrames;
        }
      }
      if (causalAsyncStacks) {
        var asyncCausalStackFrames = stack[kAsyncCausalStackFrames];
        if (asyncCausalStackFrames != null) {
          return asyncCausalStackFrames;
        }
      }
      return stack[kStackFrames] ?? [];
    }
  
    static final _history = [''];
  