Correct way to update bmake and bootstrap-mk-files?

[walt <wa1ter%myrealbox.com@localhost>]

Whenever the bmake and bootstrap-mk-files packages need updating, the
automated process fails because both of those packages are needed to
do the update ==> chicken-and-egg problem.

I use my own hacks to get around the problem but I'm wondering what a
newbie would do in the same situation.  There must be an elegant way to
do these updates, but what is it?

I've been using Peter Schuller's wip/pkgmanager package because it seems
less painful to me than pkg_chk.

What are you other clever people using to update your pkgsrc packages?