This is only example of usage of the glib package to build bindings for GTK. It isn't suitable for writing real applications. If you need working GTK binding see go-gtk or fork this project and write missing features.
See examples directory to find out what my approach is different from the go-gtk.
You need gtk 2.0 library with C header files to install this package (libgtk2.0-dev on Debian/Ubuntu).