Hi Tau,
the gtk backend does not comes loaded by default, you need to load it: Metacello new repository: 'github://pharo-spec/Spec-Gtk'; baseline: 'SpecGtk'; onConflict: [ :e | e useIncoming ]; onUpgrade: [ :e | e useIncoming ]; load. and of course, remember you need gtk3 in your system :) check here: https://github.com/pharo-spec/Spec-Gtk cheers! Esteban On Jul 19 2021, at 12:15 am, jbn126859530.7 <t...@cedalion.info> wrote: > > Hi. > > I'm learning Spec 2.0 with the help of the book "Building user interface with > Spec 2.0". In section 2.17 of the book, the authors make a subclass of > SpGtkConfiguration. However, no such class exists, only a > SpMorphicConfiguration. Moreover, if I do something like: "app useBackend: > #Gtk", I get a NotFound error. Again, "app useBackend: #Morphic" work as > intended. As Pharo 9 annonced the availability of a GTK backend, I would like > to know how to access it. > > Thanks. > > tau.