r320183 (rpc.lockd cleanup) breaks virtualbox-ose build

This is a really strange problem ...

Last week I upgraded my 12.0-CURRENT package build box from r318774 to
r320570.  I also upgraded the poudriere jail to match.  When I went to
build packages, the virtualbox-ose build failed due to ar segfaulting.

To debug I created a new 12.0-CURRENT poudriere jail with rev r318774
and the build passed.   I then bisected, which took most of the last
week, and found that this commit is what is causing the breakage:

  r320183 | delphij | 2017-06-20 23:34:06 -0700 (Tue, 20 Jun 2017) | 12 lines

  Reduce code duplication in rpc.lockd.

  Reuse create_service code instead of duplicating it in
  lookup_addresses for kernel NLM.

  As a (good) side effect this also fixed a few issues that were
  already fixed in the former but never applied to the latter.

and it only touches usr.sbin/rpc.lockd/lockd.c.

If I rebuild the r320570 jail with the r320183 change backed out, and
then I can successfully build virtualbox-ose.  I confirmed this on
another machine.

I have no idea why the rpc.lockd source would affect ar inside a
poudriere jail where NFS isn't used.  Like I said, really strange ...
ex