anchor.diff:        },
         (e, chain) {
           if (e is DartdocFailure) {
  -          stderr.writeln('\ndartdoc failed: $e.');
  +          stderr.writeln('\n$_dartdocFailedMessage: $e.');
             exitCode = 1;
           } else {
  -          stderr.writeln('\ndartdoc failed: $e\n$chain');
  +          stderr.writeln('\n$_dartdocFailedMessage: $e\n$chain');
             exitCode = 255;
           }
         },
  
positive.code: 
  import 'dart:async';
  import 'dart:convert';
  import 'dart:io' show exitCode, stderr;
  
  import 'package:analyzer/file_system/file_system.dart';
  import 'package:dartdoc/options.dart';
  
negative.code: 
    DartdocResults(this.packageMeta, this.packageGraph, this.outDir);
  }
  
  String get _dartdocFailedMessage =>
      'dartdoc $packageVersion (${Platform.script.path}) failed';
  