- Properly setup an Api scope before calling out through the API.

tests/language/deferred_in_isolate_app.dart

+// Copyright (c) 2014, 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 'deferred_in_isolate_lib.dart' deferred as test;
+
+void main(args, msg) {
+  assert(args != null);
+  assert(args.length == 1);
+  assert(msg != null);
+  assert(msg.length == 1);
+
+  var expectedMsg = args[0];
+  var replyPort = msg[0];
+
+  try {
+    print("BeforeLibraryLoading");
+
+    test.loadLibrary().then((_) {
+      var obj = new test.DeferredObj(expectedMsg);
+      replyPort.send(obj.toString());
+    }).catchError((error) {
+      replyPort.send("Error from isolate:\n$error");
+    });
+  } catch (exception, stacktrace) {
+    replyPort.send("Exception from isolate:\n$exception\n$stacktrace");
+  }
+}