packages file in
profiles/ controls the packages pulled in by the
@system set. The
base/packages file must not be modified without
discussion on the
gentoo-dev list; subprofile overrides are up to the
relevant arch teams.
packages can be used to require that specific versions of a package
be used, for example
<sys-kernel/linux-headers-2.5 in a profile requiring
a 2.4 kernel. If this is done with the intention of requiring only a lower version
(that is to say, not a > or >= restriction, and with slots not affecting the
outcome), then the entry in
packages must be accompanied by a corresponding
package.mask entry to ensure that no other versions get installed.