Still, check /etc/make.conf.I don't remember touch even single configuration file in /etc
I am using 12.3 stable.Why don’t you try at first with the standard kernel shipped with 13.1 or whatever you are running?
Just to rule out all potential sources of error…
This means something went wrong somewhere in your build.linker_load_file: /boot/kernel/linux.ko - unsupported file type