The bug does not appear to be because I'm using an old version of Gtk. if I type dpkg -l libgtk2.0-0 libgtk-3-0
I get : +++-=================-================-============-===========================> ii libgtk-3-0:amd64 3.24.20-0ubuntu1 amd64 GTK graphical user interfac> ii libgtk2.0-0:amd64 2.24.32-4ubuntu4 amd64 GTK graphical user interfac> lines 1-7/7 (END) So I'm using 3.24.20 - which should be OK. I have added the above comment to the relevant issue on github: https://github.com/pharo-spec/gtk-bindings/issues/1 I think the issues log is perhaps the better place to discuss the issue rather than this message list. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html