App chooser not showing all applications?

[Amy C <mathematical coffee gmail com>]

Hi all,

I'm trying to bring up a Gtk.AppChooserWidget with a list of all
applications on the computer for the user to select from.

However, I notice that there are quite a few apps missing (for example
the Terminal (I'm on Linux)). It may or may not be related that a few
apps (e.g. Nautilus, which shows up as 'Files', or Epiphany, which
shows up as 'Web') appear multiple times on the list.

I'm using the javascript bindings (via GJS):

    /* bring up a dialogue for them to set windows */
        let dialog = new Gtk.AppChooserDialog(this.get_toplevel(),
                Gtk.DialogFlags.MODAL | Gtk.DialogFlags.DESTROY_WITH_PARENT),
            widget = dialog.get_widget();
        dialog.set_heading(_("Select an app to blacklist/whitelist"));
        widget.set_show_all(true); // set the appchooser to show every
application

I was under the impression that the `.set_show_all(true)` would cause
every application to appear on the list - why would some not show
(such as the Terminal application which is definitely installed!)

cheers