Fix version_negotiation_test timing out.

sdk/lib/_internal/pub/lib/src/solver/dependency_queue.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 pub.solver.dependency_queue;
 
 import 'dart:async';
 import 'dart:collection' show Queue;
 
 import '../log.dart' as log;
@@ skipping 107 matching lines @@
       _isSorted = true;
     });
 
     return _sortFuture;
   }
 
   /// Given a dependency, returns a future that completes to the number of
   /// versions available for it.
   Future<int> _getNumVersions(PackageDep dep) {
     // There is only ever one version of the root package.
-    if (dep.isRoot) {
-      return new Future.value(1);
-    }
+    if (dep.isRoot) return new Future.value(1);
 
-    return _solver.cache.getVersions(dep.toRef()).then((versions) {
-      return versions.length;
-    }).catchError((error, trace) {
-      // If it fails for any reason, just treat that as no versions. This
-      // will sort this reference higher so that we can traverse into it
-      // and report the error more properly.
-      log.solver("Could not get versions for $dep:\n$error\n\n$trace");
-      return 0;
-    });
+    return _solver.cache.getVersions(dep.toRef())
+        .then((versions) => versions.length);
   }
 }