Forgot how to set up cvsup

I'm trying to set up cvsup on a new machine to snarf the postgres cvs
repository. I've had my machine at home set up for so long, I can't
remember how the $CVSROOT/CVSROOT part of my local repository directory
tree came into being. Should it be imported from postgresql.org as is
the pgsql part of the repository? Or should I set it up locally?

I'd expect it to come in from the master site, as part of the update.
I'm not sure how the collections are set up in postgresql. In the
FreeBSD project, we have a collection "src-base" that contains
$CVSROOT/CVSROOT and little else. Then there are separate collections
for various large parts of the source tree. Finally, there is a sort
of mega-collection which is equivalent to all of that put together in
a single collection.

John