installed ports dependency tree?

[Robert Huff]

	Suppose I have installed ports A..Z.  Some of these are
standakone; some depend on others on the list; others depend on
installed ports not on the list.
	Is there a port that will produce a unified and ordered
dependency list, such that upgrading/reinstalling in that order will
avoid multiple rebuilds?  I though portupgrade could to this, but
apparently not.


					Robert Huff