Dear Goran, I confirm that gtkglext is not installed, anyhow, here is the list of gtk installed libraries: gtk-engines-2 gtk-engines-2 - GTK+ Theme Engines gtk+-x11-3.0 GTK+ - GTK+ Graphical UI Library gtk+-broadway-3.0 GTK+ - GTK+ Graphical UI Library gtk+-unix-print-2.0 GTK+ - GTK+ Unix print support gtkmm-3.0 gtkmm - C++ binding for the GTK+ toolkit gtk+-unix-print-3.0 GTK+ - GTK+ Unix print support gtk+-wayland-3.0 GTK+ - GTK+ Graphical UI Library gtk+-2.0 GTK+ - GTK+ Graphical UI Library (x11...
target_link_libraries missing -lX11