that it is better to error out when people attempt to build using the
wrong bsd.*.mk files, than to silently ignore the problem.
This means, that after this commit, if you want to build kernel modules
by hand (or via a port) from a head source tree, you *must* make sure
the files in /usr/share/mk are in sync with that tree. If that isn't
possible, for example when you are running on an older FreeBSD branch,
you can:
- Run "make buildenv" from your head source tree, to have the correct
environment setup. (It's advisable to have run "make buildworld", or
at a minimum "make toolchain" first.)
- Alternatively, set MAKESYSPATH to the share/mk directory under your
head source tree. If your build tools are too old, other problems may
still occur.
- Alternatively, use "make -m" and specify the share/mk directory under
your head source tree. Again, build tools that are too old may still
result in trouble.
MFC after: 2 weeks
ae227ddf7f