I promised to report how the build process went. I forgot to mention
that my platform is amiga.

Anyway the build had failed in make depend in sys/lib/libkern with the
following:

===> libkern
make: don't know how to make adddi3.c. Stop
*** Error code 2

Stop.

So how can this happen? The file adddi3.c is there. I was trying to
build with obj directories this time. Maybe I did that wrong. Which
variables should one set for the obj directories to work correctly?
Or could my make be too old (from may I think)? Were there changes to
make recently?