From: Prarit Bhargava on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2240#note_1232744...
@jforbes (and everyone else), I had to make some additional fixes to the Makefile.variables file, and had to rethink the makefile change. It might be best to move the makefile code back into the Makefile but I'll leave that up to you to decide if you want me to move it.
Also, as requested, I've added an ENABLE_WERROR Makefile.variables variable. As you can see it forces CONFIG_WERROR=y in all arches.