2009/1/13 Chris Lieb <chris.lieb@gmail.com>

> I've noticed lately on the ML that people have been talking about using
> package sets, such as @world and @installed.  I figured it was a part of
> portage 2.1.6* since using @world with 2.1.4* would result in an error
> message about an invalid package atom.  However, after upgrading to
> portage 2.1.6.4, I still get the same error when doing something like
> 'emerge -up @world'.
>
> What are these package sets?  What is the difference between 'emerge -up
> world' and 'emerge -up @world'?  Why don't these package sets ever work
> for me?
>
> Thanks,
> Chris
>
>
A set is basically just group of packages, you can either define you own
using /etc/portage/ or using gentoo provided ones like @world and @system
(which will replace the current emerge system/world usage eventually),
aswell as useful sets such as @live-rebuild (any package that uses a
cvs/svn/git eclass, so basically any -9999 ebuild) and @module-rebuild which
is handy for rebuilding kernel modules. Also id imagine meta-packages will
eventually move over to sets as it makes rebuilding everything or removing
it much easier, currently theres only kde4 that makes large usage of sets
but id imagine once portage 2.20 goes stable we'l see great set adoption.
An easy way to see what sets are available is to use the emerge --list-sets
command.

-Nick