如何让某个包不被--depclean删除（已解决）

# emerge --depclean -p
!!! CONFIG_PROTECT is empty
 * Depclean may break link level dependencies. Thus, it is
 * recommended to use a tool such as `revdep-rebuild` (from
 * app-portage/gentoolkit) in order to detect such breakage.
 * 
 * Always study the list of packages to be cleaned for any obvious
 * mistakes. Packages that are part of the world set will always
 * be kept. They can be manually added to this set with
 * `emerge --noreplace <atom>`. Packages that are listed in
 * package.provided (see portage(5)) will be removed by
 * depclean, even if they are part of the world set.
 * 
 * As a safety measure, depclean will not remove any packages
 * unless *all* required dependencies have been resolved. As a
 * consequence, it is often necessary to run `emerge --update
 * --newuse --deep world` prior to depclean.

Calculating dependencies... done!

>>> These are the packages that would be unmerged:

 sys-kernel/gentoo-sources
 selected: 2.6.26-r3 2.6.26-r4 
 protected: none 
 omitted: 2.6.28 

>>> 'Selected' packages are slated for removal.
>>> 'Protected' and 'omitted' packages will not be removed.

Packages installed: 1103
Packages in world: 128
Packages in system: 51
Required packages: 1101
Number to remove: 2

sys-kernel/gentoo-sources:2.6.26*