Can't use diff in CVSweb

[Mark Koopman]

Scoured the web for this information but haven't come up with
anything.  Wasn't able to search this mailling list archives
either - got this message "Unable to read document excerpts '/usr/local/mailman/archives/private/freebsd-cvsweb/htdig/db.excerpts'
Did you run htdig?"

But here's my real question would love it if anyone could shed some
light... when I click a "prefered" link in CVSweb to get a diff, 
I get this error written out to the browser:

  /usr/bin/rcsdiff  -q  -u -p  -r1.8.12.3 -r1.8.12.4
  rcsdiff: can't make temporary pathname `/tmp/rcsIBYrHv/T0XXXXXX'
  rcsdiff aborted

I've tried all the obvious (chmod -R 777 /tmp; chown -R nobody /tmp)
but still nada enchilada.