make installworld for i386 fails on Kyuafile

I was successful on make buildworld and kernel, but make installworld failed on a missing file somewhere:

/usr/share/man/man3/pmclog_read.3.gz -> /usr/share/man/man3/pmclog.3.gz
===> lib/libproc (install)
install -C -o root -g wheel -m 444   libproc.a /usr/lib
install -C -o root -g wheel -m 444   libproc_p.a /usr/lib
install -s -o root -g wheel -m 444     libproc.so.2 /usr/lib
install -l s libproc.so.2 /usr/lib/libproc.so
install -C -o root -g wheel -m 444  /BETA1/usr/src/lib/libproc/libproc.h /usr/include
===> lib/libproc/tests (install)
install -o root  -g wheel -m 444  Kyuafile.auto  /usr/tests/lib/libproc/Kyuafile
install: /usr/tests/lib/libproc/Kyuafile: No such file or directory
*** Error code 71

Stop.
bmake[6]: stopped in /BETA1/usr/src/lib/libproc/tests
*** Error code 1


svn revision is 271942.

I never had this particular error happen before, even though I've had successful builds and installs subsequent to 20140110 (referring to UPDATING; I never used NO_CLEAN).

What could have happened this time?  Shouuld I follow the directions in UPDATING 20140110 and

find /BETA1/usr/obj.i386 -name Kyuafile | xargs rm -f     ? 

or svn update and rebuild, but this time running rm -R /BETA1/usr/obj.i386/* before rebuilding?

Or is there a bug?

Tom