idea for adding new feature named "backup" ok, if I add into FEATURES="backup", then if i unemerge package, or update packate, the old package backuped with "quick_package" tool automatically. this is very usable feature for server instalations and backward copy of updated packages. Reproducible: Always Steps to Reproduce:
why not use buildpkg generally?
because buildpkg is creating pkg for new package and is not backuping the old one which is to be unemerged.
buildpkg will build a pkg regardless of whether what you just emerged is new or an upgrade
It would be nice to have a feature, which would do backup of original package with its config options. Original package is usually the one stable and I would like to be able to get instantially back to it if new merged package is proved to be faulty in some way. This is essential in server production environment (less in desktop environment).
I vote for this feature allowing your system to roll back to a previous state - package by package. emerge has to gain more power regarding roll-on and roll-back your system. See also http://bugs.gentoo.org/show_bug.cgi?id=54113 - not the same, but an similar idea. In combination with collision-protect feature we could also use a collision-backup feature, that backs up files - that will be overwritten *if not belonging to the upgrading package*
