<reading the mailing-list through the archive gateway>

Over in OpenBSD, we have some experience with a similar mechanism

It's called SUPDISTFILES

SUPDISTFILES contains an extra list of DISTFILES that may be desireable:
arch-dependent stuff, things activated only through some options.

The idea is that the union of DISTFILES, PATCHFILES and SUPDISTFILES
will cover everything a port would ever need.

For simplicity, DISTFILES and SUPDISTFILES may contain some of the same
files. For instance, it's ways simpler to have a set of tests for 
arch-dependent DISTFILES, and then to simply list everything in SUPDISTFILES
as well.

SUPDISTFILES is used for makesum, obviously, and also mirroring distfiles.

There's a target fetch-all that is devoted to fetching everything.

A minor misdesign is that fetch-all simply invokes fetch with __FETCH_ALL
set to Yes, and we have conditionals that add to the set of files being
fetched in such a case.

It would be way cleaner to have fetch and fetch-all be targets in their
own rights, and use slightly different internals.

But this doesn't impeded the usefulness of it all.

For one thing, SUPDISTFILES has helped us a lot in setting mirrors,
and also in making sure people do not end up having partial distinfo
files.