anchor.diff:      // make modifiable copy
       dartdocPubspec = JSON.decode(JSON.encode(dartdocPubspec)) as Map;
   
  -    dartdocPubspec['dependencies']['markdown'] = {
  -      'git': {
  -        'url': 'git://github.com/dart-lang/markdown.git',
  -        'ref': markdownRef
  -      }
  -    };
  +    if (markdownRef == 'local') {
  +      dartdocPubspec['dependencies']['markdown'] = {
  +        'path': markdownPath,
  +      };
  +    } else {
  +      dartdocPubspec['dependencies']['markdown'] = {
  +        'git': {
  +          'url': 'git://github.com/dart-lang/markdown.git',
  +          'ref': markdownRef
  +        }
  +      };
  +    }
   
       new File(dartdocPubspecPath).writeAsStringSync(JSON.encode(dartdocPubspec));
  -    return _system('pub', ['get']);
  +    return _system('pub', ['upgrade']);
     }
   }
   
  
positive.code:   final String dartdocBin;
    final String dartdocPubspecPath;
    final bool sdk;
  
    DartdocCompare(this.dartdocDir, this.markdownBefore, this.markdownAfter,
        this.dartdocBin, this.dartdocPubspecPath, this.sdk);
  
    bool compare(String package) {
      // Generate docs with Markdown "A".
      var outBefore = _runDartdoc(markdownBefore, package);
  
      // Generate docs with Markdown "B".
      var outAfter = _runDartdoc(markdownAfter, package);
  
      // Compare outputs
  
negative.code:     ..addOption(_dartdocDir, help: "Directory of the dartdoc package")
      ..addOption(_markdownBefore, help: "Markdown package 'before' ref")
      ..addOption(_markdownAfter,
          defaultsTo: "HEAD", help: "Markdown package 'after' ref (or 'local')")
      ..addFlag(_sdk,
          defaultsTo: false, negatable: false, help: "Is the package the SDK?")
      ..addFlag(_help, abbr: "h", hide: true);
  