RFC: building with non-default options on universe machines?

Hi,

This is a really dump question, but since I've tried a
few times without success, I figured I'd ask..

I need to do a "make buildworld" with WITHOUT_MITKRB5="yes"
set. I'd like to do it on one of the unverse machines, but I cannot
get it to work.

I put WITHOUT_MITKRB5="yes" in a file and tried both
SRCCONF=../src.conf and __MAKE_CONF=../src.conf.
They both would fail at some point, because other things
that depend on the setting would fail.

So, does anyone know what the trick is?

Thanks in advance for any comments, rick