libgtk3-perl 0.034-1 (amd64 binary) in ubuntu cosmic

 GTK+ is a multi-platform toolkit for creating graphical user
 interfaces. Offering a complete set of widgets, GTK+ is suitable
 for projects ranging from small one-off tools to complete application
 suites.
 .
 This package contains the Perl bindings to GTK+, built using
 Glib::Object::Introspection. Generated bindings live under the Gtk3 namespace.