Fix several package spec bugs.

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.
 
 library pub.entrypoint;
 
 import 'dart:async';
 
 import 'package:path/path.dart' as path;
 import 'package:barback/barback.dart';
@@ skipping 452 matching lines @@
   ///
   /// If [result] is passed, this loads the graph from it without re-parsing the
   /// lockfile or any pubspecs. Otherwise, before loading, this makes sure the
   /// lockfile and dependencies are installed and up to date.
   Future<PackageGraph> loadPackageGraph([SolveResult result]) async {
     if (_packageGraph != null) return _packageGraph;
 
     var graph = await log.progress("Loading package graph", () async {
       if (result != null) {
         var packages = await Future.wait(result.packages.map((id) async {
+          if (id.name == root.name) return root;
+
           var dir = await cache.sources[id.source].getDirectory(id);
           return new Package(result.pubspecs[id.name], dir);
         }));
 
         return new PackageGraph(this, new LockFile(result.packages),
             new Map.fromIterable(packages, key: (package) => package.name));
       }
 
       await ensureLockFileIsUpToDate();
       var packages = await Future.wait(lockFile.packages.values.map((id) async {
@@ skipping 75 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 = path.join(dir, 'packages');
     if (entryExists(symlink)) deleteEntry(symlink);
     if (_packageSymlinks) createSymlink(packagesDir, symlink, relative: true);
   }
 }