[gtkada] Pb compilating GtkAda-2.2.0

[Adrien de Sentenac]

I try to compile GtkAda with gnat 3.15p under linux

configure goes well, compilation too till i get :

gnatbind -x gate.ali
gnatlink -o gate-in.exe -L. -lgtkada -lgtk-x11-2.0 -lgdk-x11-2.0 -latk-1.0
-lgdk_pixbuf-2.0 -lm -lpangoxft-1.0 -lpangox-1.0 -lpango-1.0 -lgobject-2.0
-lgmodule-2.0 -ldl -lglib-2.0 gate.ali
./libgtkada.so: undefined reference to `gdk_screen_get_default'
./libgtkada.so: undefined reference to `gdk_screen_get_root_window'
gnatlink: cannot call /usr/gnat/bin/gcc
gnatmake: *** link failed.
make[1]: *** [gate-in.exe] Erreur 4
make[1]: Quitte le répertoire `/home/adrien/GtkAda-2.2.0src/src'
make: *** [install] Erreur 2


does someone know where my problem comes from ? and what can i do to fix it ?