Created attachment 196469 [details]
buildkernel error log
If world is built with WITHOUT_LEGACY_CONSOLE=true, building a kernel with options like:
fails with the errors from the attached file.
As far as I can see, this is due to the fact that if option KBDMUX_DFLT_KEYMAP is used, kbdcontrol is a build tool (see sys/conf/files and the "kbdmuxmap.h ... compile-with kbdcontrol ..." line) and it is not installed, and removed by make delete-old if present, if WITHOUT_LEGACY_CONSOLE=true is in src.conf.
It seems that kbdcontrol should be built and installed even if WITHOUT_LEGACY_CONSOLE is true. Note that its man page states it is not specific to the legacy console :
The kbdcontrol command is used to set various keyboard related options
for the syscons(4) or vt(4) console driver and the keyboard drivers