Fix an edge case in dependency freshness checking.

lib/src/entrypoint.dart

 // Copyright (c) 2012, 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.
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:barback/barback.dart';
 import 'package:package_config/packages_file.dart' as packages_file;
 import 'package:path/path.dart' as p;
@@ skipping 518 matching lines @@
       }
 
       dataError('${p.join(source.getDirectory(id), 'pubspec.yaml')} has '
           'changed since the pubspec.lock file was generated, please run "pub '
           'get" again.');
     }
   }
 
   /// Returns whether the locked version of [dep] matches the dependency.
   bool _isDependencyUpToDate(PackageDep dep) {
+    if (dep.name == root.name) return true;
+
     var locked = lockFile.packages[dep.name];
     if (locked == null) return false;
 
     if (dep.source != locked.source) return false;
 
     if (!dep.constraint.allows(locked.version)) return false;
 
     var source = cache.sources[dep.source];
     if (source == null) return false;
 
@@ skipping 131 matching lines @@
   /// If [packageSymlinks] is true, creates a symlink to the "packages"
   /// directory in [dir].
   ///
   /// Otherwise, deletes a "packages" directories in [dir] if one exists.
   void _linkOrDeleteSecondaryPackageDir(String dir) {
     var symlink = p.join(dir, 'packages');
     if (entryExists(symlink)) deleteEntry(symlink);
     if (_packageSymlinks) createSymlink(packagesDir, symlink, relative: true);
   }
 }