"pub cache repair" prints a more detailed summary.

test/version_solver_test.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_upgrade_test;
 
 import 'dart:async';
 
 import 'package:pub/src/lock_file.dart';
 import 'package:pub/src/log.dart' as log;
@@ skipping 1419 matching lines @@
       return _packages[id.description][id.version].pubspec;
     });
   }
 
   Future<Package> downloadToSystemCache(PackageId id) =>
       throw new UnsupportedError('Cannot download mock packages');
 
   List<Package> getCachedPackages() =>
       throw new UnsupportedError('Cannot get mock packages');
 
-  Future<Pair<int, int>> repairCachedPackages() =>
+  Future<Pair<List<Package>, List<Package>>> repairCachedPackages() =>
       throw new UnsupportedError('Cannot repair mock packages');
 
   void addPackage(String description, Package package) {
     _packages.putIfAbsent(description, () => new Map<Version, Package>());
     _packages[description][package.version] = package;
   }
 }
 
 Package mockPackage(PackageId id, Map dependencyStrings, Map overrides) {
   var sdkConstraint = null;
@@ skipping 81 matching lines @@
   }
 
   var source = "mock1";
   if (match[7] != null) {
     source = match[7];
     if (source == "root") source = null;
   }
 
   return new PackageId(name, source, parsedVersion, description);
 }