ports/129891: ports-mgmt/portupgrade fails to recognize variations of dependencies

[Igor Roshchin]

First, just a correction:
I think, it is actually ALT_PKGDEP (not ALT_DEPENDS).

Second, it is nice that that mechanism is there.
It would be nice now, if there was a default list of
alternative dependencies provided as a part of the ports collection
(alongside INDEX, or something like that).
This way it would get updated with the ports collection evolving.
This "feature suggestion" goes beyond just "portupgrade", and would be a 
greate improvement for the entire ports collection.
So, I am not sure what is the best way of submitting it, - so I hope 
somebody can route it correctly.