Use "package:" imports for pub.

test/lish/force_cannot_be_combined_with_dry_run_test.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.
 
+import 'package:pub/src/exit_codes.dart' as exit_codes;
 import 'package:scheduled_test/scheduled_test.dart';
 
-import '../../lib/src/exit_codes.dart' as exit_codes;
 import '../descriptor.dart' as d;
 import '../test_pub.dart';
 
 main() {
   initConfig();
   setUp(d.validPackage.create);
 
   integration('--force cannot be combined with --dry-run', () {
     schedulePub(args: ['lish', '--force', '--dry-run'],
         error: """
           Cannot use both --force and --dry-run.
           
           Usage: pub publish [options]
           -h, --help       Print this usage information.
           -n, --dry-run    Validate but do not publish the package.
           -f, --force      Publish without confirmation if there are no errors.
               --server     The package server to which to upload this package.
                            (defaults to "https://pub.dartlang.org")
 
           Run "pub help" to see global options.
           See http://dartlang.org/tools/pub/cmd/pub-lish.html for detailed documentation.
           """,
         exitCode: exit_codes.USAGE);
   });
 }