Sabayon/for-gentoo — pull request #24 by matijaskala (2014-01-20 13:01:04+00:00)
Title: The ebuild fails if gtk3 is not installed.

Problem lies in introspection support: 'NMGtk-1.0.gir' includes 'Gtk-3.0.gir' which may not exist on some systems.
This sed command replaces 'Gtk-3.0.gir' with 'Gtk-2.0.gir' which is in the gtk2 package.