anchor.diff:  // foo/bar.dart 10:11 in Foo._bar
   // http://dartlang.org/foo/bar.dart in Foo._bar
   final _friendlyFrame = new RegExp(
  -    r'^([^\s]+)(?: (\d+)(?::(\d+))?)?\s+([^\d][^\s]*)$');
  +    r'^(\S+)(?: (\d+)(?::(\d+))?)?\s+([^\d]\S*)$');
   
   final _initialDot = new RegExp(r"^\.");
   
  
positive.code:     // nesting for each eval performed on that line.
      parseLocation(location, member) {
        var evalMatch = _v8EvalLocation.firstMatch(location);
        if (evalMatch != null) return parseLocation(evalMatch[1], member);
        
  
        var urlMatch = _v8UrlLocation.firstMatch(location);
        if (urlMatch == null) {
  
negative.code: 
  // #1      Foo._bar (file:///home/nweiz/code/stuff.dart:42:21)
  final _vmFrame = new RegExp(
      r'^#\d+\s+(\S.*) \((.+?):(\d+)(?::(\d+))?\)$');
  
  //     at VW.call$0 (http://pub.dartlang.org/stuff.dart.js:560:28)
  //     at VW.call$0 (eval as fn
  //         (http://pub.dartlang.org/stuff.dart.js:560:28), efn:3:28)
  //     at http://pub.dartlang.org/stuff.dart.js:560:28
  final _v8Frame = new RegExp(
      r'^\s*at (?:(\S.*?)(?: \[as [^\]]+\])? \((.*)\)|(.*))$');
  
  // http://pub.dartlang.org/stuff.dart.js:560:28
  final _v8UrlLocation = new RegExp(r'^(.*):(\d+):(\d+)$');
  