Install barback from a hosted source in all tests.

test/transformer/asset_not_found_exceptions_are_detectable_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS d.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_tests;
 
 import 'dart:convert';
 
 import 'package:scheduled_test/scheduled_stream.dart';
 
@@ skipping 21 matching lines @@
         'package': error.id.package,
         'path': error.id.path
       })));
     });
   }
 }
 """;
 
 main() {
   integration("AssetNotFoundExceptions are detectable", () {
+    serveBarback();
+
     d.dir(appPath, [
       d.pubspec({
         "name": "myapp",
-        "transformers": ["myapp/src/transformer"]
+        "transformers": ["myapp/src/transformer"],
+        "dependencies": {"barback": "any"}
       }),
       d.dir("lib", [d.dir("src", [
         d.file("transformer.dart", transformer)
       ])]),
       d.dir("web", [
         d.file("foo.txt", "foo")
       ])
     ]).create();
 
-    createLockFile('myapp', pkg: ['barback']);
-
+    pubGet();
     var server = pubServe();
     requestShouldSucceed("foo.txt", JSON.encode({
       "package": "myapp",
       "path": "nonexistent"
     }));
     endPubServe();
 
     // Since the AssetNotFoundException was caught and handled, the server
     // shouldn't print any error information for it.
     server.stderr.expect(isDone);
   });
 }