So, I can compile /usr/src using build.sh to make releases, but if I
do it more than twice in a row with softdep enabled, I get a crash
and/or lockup.  It appears that blocks are not being flushed to disk,
but it's hard to tell for certain what exactly is going on.

With softdep off, I can build constantly (as long as /usr/src actually
builds due to lots of recent changes :)

--Michael