I’ve been trying to use an overlay to configure set some Emacs build
options – dropping GTK3 in favor of GTK2/Athena. In doing so, no build
that I’ve had has done so. How can I go about doing so?
It seems to me that a more robust and elegant solution would achieve the same by overriding toolkit with "gtk2" or "lucid", but I couldn’t/didn’t figure out how to do that.
Welcome to the community. After checking the generic emacs expression, it appears that you must provide a gtk[23]-x11 as part of the override, as by default they are both set to null. Try passing them from super. Also, if I understood you correctly (I don’t use emacs so I don’t know), you are trying to use gtk2, but in your expression you have gtk2 set to false.