Link to stable-errors site from pub-build messages on the command line.

pkg/polymer/test/build/common.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library polymer.test.build.common;
 
 import 'dart:async';
 
 import 'package:barback/barback.dart';
 import 'package:code_transformers/messages/build_logger.dart'
@@ skipping 56 matching lines @@
       expect(result.succeeded, !errorSeen, reason: "${result.errors}");
     });
 
     logSubscription = barback.log.listen((entry) {
       // Ignore info messages.
       if (entry.level == LogLevel.INFO || entry.level == LogLevel.FINE) return;
       if (entry.level == LogLevel.ERROR) errorSeen = true;
       // We only check messages when an expectation is provided.
       if (messages == null) return;
 
-      var msg = '${entry.level.name.toLowerCase()}: ${entry.message}';
+      var errorLink = new RegExp(
+          ' See http://goo.gl/5HPeuP#polymer_[0-9]* for details.');
+      var text = entry.message;
+      var newText = text.replaceFirst(errorLink, '');
+      expect(text != newText, isTrue);
+      var msg = '${entry.level.name.toLowerCase()}: ${newText}';
       var span = entry.span;
       var spanInfo = span == null ? '' :
           ' (${span.sourceUrl} ${span.start.line} ${span.start.column})';
       var index = messagesSeen++;
       expect(messagesSeen, lessThanOrEqualTo(messages.length),
           reason: 'more messages than expected.\nMessage seen: $msg$spanInfo');
       expect('$msg$spanInfo', messages[index]);
     });
   }
 
@@ skipping 155 matching lines @@
 
   'observe|lib/observe.dart':
       'library observe;\n'
       'export "src/metadata.dart";',
 
   'observe|lib/src/metadata.dart':
       'library observe.src.metadata;\n'
       'class ObservableProperty { const ObservableProperty(); }\n'
       'const observable = const ObservableProperty();\n',
 };