Created attachment 296797 [details]
Generated C file

I have following interface:
[DBus (name="org.some.interface")]
interface SomeInterface: Object
{
	public abstract void context_menu(int x, int y);
	public abstract void activate(int x, int y);
	public abstract void secondary_activate(int x, int y);
	public abstract void scroll(int delta, string orientation);
}

After trying to build it I get this error:
snitem.c: In function ‘some_interface_proxy_context_menu’:
snitem.c:185:228: error: ‘error’ undeclared (first use in this function)
  _reply_message = g_dbus_connection_send_message_with_reply_sync (g_dbus_proxy_get_connection ((GDBusProxy *) self), _message, G_DBUS_SEND_MESSAGE_FLAGS_NONE, g_dbus_proxy_get_default_timeout ((GDBusProxy *) self), NULL, NULL, error);
                                                                                                                                                                                                                                    ^
snitem.c:185:228: note: each undeclared identifier is reported only once for each function it appears in
snitem.c: In function ‘some_interface_proxy_activate’:
snitem.c:209:228: error: ‘error’ undeclared (first use in this function)
  _reply_message = g_dbus_connection_send_message_with_reply_sync (g_dbus_proxy_get_connection ((GDBusProxy *) self), _message, G_DBUS_SEND_MESSAGE_FLAGS_NONE, g_dbus_proxy_get_default_timeout ((GDBusProxy *) self), NULL, NULL, error);
                                                                                                                                                                                                                                    ^
snitem.c: In function ‘some_interface_proxy_secondary_activate’:
snitem.c:233:228: error: ‘error’ undeclared (first use in this function)
  _reply_message = g_dbus_connection_send_message_with_reply_sync (g_dbus_proxy_get_connection ((GDBusProxy *) self), _message, G_DBUS_SEND_MESSAGE_FLAGS_NONE, g_dbus_proxy_get_default_timeout ((GDBusProxy *) self), NULL, NULL, error);
                                                                                                                                                                                                                                    ^
snitem.c: In function ‘some_interface_proxy_scroll’:
snitem.c:257:228: error: ‘error’ undeclared (first use in this function)
  _reply_message = g_dbus_connection_send_message_with_reply_sync (g_dbus_proxy_get_connection ((GDBusProxy *) self), _message, G_DBUS_SEND_MESSAGE_FLAGS_NONE, g_dbus_proxy_get_default_timeout ((GDBusProxy *) self), NULL, NULL, error);

It obliviosly not builds.