mono$ mono bin/Debug/TestGtkBinding.exe

(<unknown>:29072): Gtk-CRITICAL **: gtk_label_set_label: assertion `str != NULL' failed

(<unknown>:29072): Gtk-CRITICAL **: gtk_label_set_label: assertion `str != NULL' failed

(<unknown>:29072): Gtk-CRITICAL **: gtk_label_set_label: assertion `str != NULL' failed
*** glibc detected *** free(): invalid pointer: 0x08466804 ***

=================================================================
Got a SIGABRT while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries
used by your application.
=================================================================

Stacktrace:

in (wrapper managed-to-native) System.Object:__icall_wrapper_mono_ftnptr_to_delegate (intptr,intptr) <0x4>
in (wrapper managed-to-native) System.Object:__icall_wrapper_mono_ftnptr_to_delegate (intptr,intptr) <0xffffff1b>
in (wrapper managed-to-native) Gtk.Bondage.ListAdaptor:gtksharp_node_store_set_tree_model_callbacks (intptr,Gtk.Bondage.ListAdaptor/TreeModelIfaceDelegates&) <0xfffffdf3>
in Gtk.Bondage.ListAdaptor:BuildTreeModelIface () <0x253>
in Gtk.Bondage.ListAdaptor:.ctor (System.Collections.IList&) <0x5f>
in Gtk.Bondage.ComboBoxAdaptor:set_DataSource (System.Collections.IList) <0x94>
in MainWindow:.ctor () <0x612>
in TestGtkBinding.MainClass:Main (string[]) <0x1e>
in (wrapper runtime-invoke) System.Object:runtime_invoke_void_string[] (object,intptr,intptr,intptr) <0xc7589f49>