Created attachment 201197 [details]
It's currently impossible to configure the keyboard layout in gdm because gnome-shell forces it to use systemd localed which we don't have and gdm ends up falling back to a compiled-in default of US qwerty. This patch lets gdm obtain input source settings from dconf.
Created attachment 201647 [details]
Alternate patch (derive layout from locale)
Here is an alternate patch which does not depend on dconf settings but instead derives the keyboard layout from the locale.
FreeBsd 12.0-Release-p3 Generic
First patch (Tijl Coosemans) failed.
"Hunk #1 failed at 3"
Second patch (Thomas Quinot) applies successfully,
but has no effect on gdm keyboard layout.