Hi.

gnome-control-center-3.8.4 and GLib 2.36.3.

It seems panels/datetime/timedated.c is not shipped in the gnome-control-center tarball anymore; so it gets generated with gdbus-codegen.
On OpenBSD, the build fails with:
timedated.c: In function 'timedate1_proxy_get_type':
timedated.c:1252: error: expected expression before 'Timedate1Proxy'
timedated.c:1252: error: expected ';' before '{' toke

Here's a diff between the old shipped timedated.c (working) and the new generated one (not working).

--- /usr/ports/pobj/gnome-control-center-3.8.3/gnome-control-center-3.8.3/panels/datetime/timedated.c   Sat Jun  8 00:44:02 2013
+++ /usr/ports/pobj/gnome-control-center-3.8.4/gnome-control-center-3.8.4/panels/datetime/timedated.c   Thu Jul 25 08:59:05 2013
@@ -1,5 +1,5 @@
 /*
- * Generated by gdbus-codegen 2.37.0. DO NOT EDIT.
+ * Generated by gdbus-codegen 2.37.5. DO NOT EDIT.
  *
  * The license of this code is the same as for the source it was derived from.
  */
@@ -1250,6 +1250,7 @@
 static void timedate1_proxy_iface_init (Timedate1Iface *iface);
 
 G_DEFINE_TYPE_WITH_CODE (Timedate1Proxy, timedate1_proxy, G_TYPE_DBUS_PROXY,
+                         G_ADD_PRIVATE (Timedate1Proxy)
                          G_IMPLEMENT_INTERFACE (TYPE_TIMEDATE1, timedate1_proxy_iface_init));
 
 static void
@@ -1294,7 +1295,7 @@
   error = NULL;
   if (!g_dbus_proxy_call_finish (proxy, res, &error))
     {
-      g_warning ("Error setting property `%s' on interface org.freedesktop.timedate1: %s (%s, %d)",
+      g_warning ("Error setting property '%s' on interface org.freedesktop.timedate1: %s (%s, %d)",
                  info->parent_struct.name, 
                  error->message, g_quark_to_string (error->domain), error->code);
       g_error_free (error);
@@ -1439,7 +1440,7 @@
 static void
 timedate1_proxy_init (Timedate1Proxy *proxy)
 {
-  proxy->priv = G_TYPE_INSTANCE_GET_PRIVATE (proxy, TYPE_TIMEDATE1_PROXY, Timedate1ProxyPrivate);
+  proxy->priv = timedate1_proxy_get_instance_private (proxy);
   g_dbus_proxy_set_interface_info (G_DBUS_PROXY (proxy), timedate1_interface_info ());
 }
 
@@ -1449,8 +1450,6 @@
   GObjectClass *gobject_class;
   GDBusProxyClass *proxy_class;
 
-  g_type_class_add_private (klass, sizeof (Timedate1ProxyPrivate));
-
   gobject_class = G_OBJECT_CLASS (klass);
   gobject_class->finalize     = timedate1_proxy_finalize;
   gobject_class->get_property = timedate1_proxy_get_property;
@@ -1882,6 +1881,7 @@
 
 static void timedate1_skeleton_iface_init (Timedate1Iface *iface);
 G_DEFINE_TYPE_WITH_CODE (Timedate1Skeleton, timedate1_skeleton, G_TYPE_DBUS_INTERFACE_SKELETON,
+                         G_ADD_PRIVATE (Timedate1Skeleton)
                          G_IMPLEMENT_INTERFACE (TYPE_TIMEDATE1, timedate1_skeleton_iface_init));
 
 static void
@@ -2041,7 +2041,7 @@
 static void
 timedate1_skeleton_init (Timedate1Skeleton *skeleton)
 {
-  skeleton->priv = G_TYPE_INSTANCE_GET_PRIVATE (skeleton, TYPE_TIMEDATE1_SKELETON, Timedate1SkeletonPrivate);
+  skeleton->priv = timedate1_skeleton_get_instance_private (skeleton);
   g_mutex_init (&skeleton->priv->lock);
   skeleton->priv->context = g_main_context_ref_thread_default ();
   skeleton->priv->properties = g_new0 (GValue, 3);
@@ -2088,8 +2088,6 @@
 {
   GObjectClass *gobject_class;
   GDBusInterfaceSkeletonClass *skeleton_class;
-
-  g_type_class_add_private (klass, sizeof (Timedate1SkeletonPrivate));
 
   gobject_class = G_OBJECT_CLASS (klass);
   gobject_class->finalize = timedate1_skeleton_finalize;