> I just read the one about excluding sendmail and amd from a build if
> DESTDIR is not defined, and that's got me concerned.

you just got a "what" point for not paying attention to the discussion.

As part of a "make release", we currently *invoke* the built sendmail
to build the original mostly-empty aliases database.  this is just
wrong for a cross-build, since you'd be (for instance) be running a
just-built NetBSD-1.5/foo binary on a "bar" host, which has no chance
of working in the general case.

> I'm one of those foolhardy people who builds things in place (and, by
> and large, it just works); do I need to set DESTDIR=/ in order to
> be sure these are built?

No.