What harm is done if we install the override without the gtk dependency?
If gtk is not there, the code will never be loaded.

Alternatively, can you write a patch that runs distcheck successfully?

Giovanni: no harm, but the logic doesn't work correctly I'm afraid.

First, gjs-gtk-util.h does not include config.h, so it will always think ENABLE_GTK is false, leading to the symbol not being exported in the library. In fact, printing the value of GjsPrivate.gtk_container_child_set_property() always gets me "undefined", even with --with-gtk=yes.

Second, the way GJS_ENABLE_GTK is defined will result in the introspection annotation to always be 1, regardless of the value of --with-gtk, which might be why you thought this should have worked previously...

Created attachment 274021 [details] [review]
Gtk: fix enabling and disabling the C override helper

We need to include "config.h" in the introspected header, so that
it knows whether to expose the function or not, and we cannot use
a constant because the introspection scanner is too limited to
recognize conditional constants. So we just check for the function
directly.

Created attachment 274024 [details] [review]
Gtk: fix enabling and disabling the C override helper

We need to include "config.h" in the introspected header, so that
it knows whether to expose the function or not, and we cannot use
a constant because the introspection scanner is too limited to
recognize conditional constants. So we just check for the function
directly.

Review of attachment 274024 [details] [review]:

Works fine and looks good - thanks.

Attachment 274024 [details] pushed as 3bcd6ba - Gtk: fix enabling and disabling the C override helper