Bastien Nocera authored Feb 26, 2019 and Adrien Plazas committed Feb 27, 2019

From the Internationalization section of the GLib API docs:
In order to use these macros in an application, you must include
<glib/gi18n.h>. For use in a library, you must include <glib/gi18n-lib.h>
after defining the GETTEXT_PACKAGE macro suitably for your library