Looks like some sort of master side global rebuild was initiated but
without the proper SVN information.  But I see a rebuild on 7.2 with
this patch revision that looks like it worked (still failed, but with a
different reason)

I'm not that familiar with the test harness, but would it be possible to
get test_multiprocessing to log an error when it has to be skipped (like
other tests that fail to find supporting modules and what not), so as to
highlight it in the log?  It might even warn about what to do to fix the
behavior for someone running the tests.

In any event though, I'm fine with enabling the support on the 7.2
buildbot (I'll stick it in loader.conf so I don't have to remember after
a reboot) if we're past any point of wanting to check how the test
behaves without them.  Or I guess the 6.4 buildbot can continue to serve
that purpose, right?