Upgrading question [CURRENT] failing buildworld

[jb_daefo]

I've a CURRENT r281990 that won't complete buildworld, nor installworld from

an obj rsynced from r285019.
and a src r285239
IOW former won't install
latter won't build...

( missing files, etc... error varies)

Just a slight chance anyone has run into a similar situation...

Current error is in /usr/src/lib/clang/libllvmsupport (file not found)
during buildworld



elsewhere,
"don't know how to make auto.obj.mk"
(usr/src/contrib/llvm/include) "make install" -- the above error occurs

I don't suspect a mismatch between src and obj (former not building, latter already
built); only a few days apart as to upgrades.



Hopefully stated clearly enough.
Not that important now, but may eventually be a showstopper.

I've checked "man build" and UPDATING and not really sure how to proceed.