[Gentoo]Clean up world file

let me name it “reverse approach”.

You first make a back up and empty your world file: 1) gentoo ~ #cp /var/lib/portage/world ~/ && >/var/lib/portage/world and then build it again: 2) gentoo ~ #regenworld

“regenworld” will put some packages which it thinks belong to the world list. Now check what portage finds to be useless when the world set is almost empty: 3) gentoo ~ #emerge –depclean –pretend

From the list shown by the above command you chose the program packages you want to have installed and put them in the world file. One “atom” (“category-name/package-name”, without version numbers) per line. Now do as “emerge –depclean” recommends:

4) gentoo ~ #emerge –update –newuse –deep world

Repeat the steps from (2) to (4) until (3) shows only packages that are not familiar to you and (4) doesn’t want to install anything.

Next. Check if there are no system packages in the list (3) shows: 5) gentoo ~ #emerge -pve system

It should not happen that (3) wants to remove system packages but its better to be sure.

Now “cross your fingers” and execute emerge –deplcean for real (without –pretend). 6) emerge –deplcean Immediately after (6) finishes you must do: 7) emerge -DuN world 8) revdep-rebuild

When (8) is successfully finished you should have a “clean” world set within a healthy system. If something goes wrong you can bring back your working “world” and recheck all packages:

#cp ~/world /var/lib/portage/world #emerge -DuN world #revdep-rebuild