Selected set (Portage)
The selected set contains the packages the admin has explicitly installed, those specified in the world and world_sets files. The selected set, together with the profile set and the system set, make up the world set. With a couple of exceptions, Portage will register selected set package atoms to the /var/lib/portage/world file.
- System set (Portage) — contains the software packages required for a standard Gentoo Linux installation to run properly.
- World set (Portage) — encompasses the system set and the selected set.
- Selected-packages_set_(Portage) — contains the user-selected "world" packages that are listed in the /var/lib/portage/world file.
- /etc/portage/sets — an optional directory that is used to create user defined package sets
- Profile (Portage) — specifies the default state of USE flags, sets default values for most variables found in /etc/portage/make.conf, defines a set of system packages, and selects available package versions.
- https://forums.gentoo.org/viewtopic-t-1042252-start-11.html - A forum thread that discusses dependency calculation using the world file.