>> 	PREV_PKGBASE for previous package name(s)
>> 	PREV_PKGPATH for previous PKGPATH(s)
> Is it really necessary to keep two variables?
> PREV_PKGPATH looks enought.

For correcting myself.
PREV_PKGBASE whould be better because every PKGBASE can be mapped
to ONLY ONE PKGPATH. Currently PKGPATH can be also be mapped to single 
PKGBASE
but this may be changed in the future when/if subpackages (you called
them subpackages, rights?) will be implemented.
Anyway it is better to treat PKGPATH just like "yet another attribute"
of a binary package which is necessary only to know where this package
was build from and is useless while working with binary packages.
BTW, PKGBASE is a part of binary package file name.
 

------------------
Форекс Клубу 10 лет! http://www.forexclub.by