You need to use an up to date version of GtkAda (e.g. GtkAda 2.2.0 that has just been announced). However, I'd not recommend building the head of gvd, which is now only used in the context of GPS, a new IDE to be released soon. If you want to build the "latest" gvd, I'd suggest using the contents of the branch-1_2_2 branch instead. Arno