import glib.*; import gobject.*; import pango.*; record Struct__GtkObject ( parent_instance : GInitiallyUnowned, flags : guint32, ); alias GtkObject = Struct__GtkObject; // remove this alias and it works alias GdkWindow = Opaque; record GtkWidget ( object : GtkObject, state : guint8, saved_state : guint8, name : Pointer[gchar], style : Pointer[Opaque], requisition : Opaque, allocation : Opaque, window : Pointer[Opaque], parent : Pointer[GtkWidget], ); private external clickedReload() { var button2 = null(GtkWidget); gSignalConnect(button2, cstring(""), GCallback(0), gpointer(0)); }