Validate packages against their SDK constraints.

utils/pub/command_update.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 command_update;
 
 import 'dart:async';
 import 'entrypoint.dart';
 import 'log.dart' as log;
 import 'pub.dart';
 
-/// Handles the `update` pub command. 
+/// Handles the `update` pub command.
 class UpdateCommand extends PubCommand {
   String get description =>
     "Update the current package's dependencies to the latest versions.";
 
   String get usage => 'pub update [dependencies...]';
 
   Future onRun() {
     var future;
     if (commandOptions.rest.isEmpty) {
       future = entrypoint.updateAllDependencies();
     } else {
       future = entrypoint.updateDependencies(commandOptions.rest);
     }
-    return future.then((_) => log.message("Dependencies updated!"));
+    return future
+        .then((_) => log.message("Dependencies updated!"))
+        .then((_) => entrypoint.validateSdkConstraints());
   }
 }