Ladislav Laska posted on Mon, 26 Oct 2009 13:55:51 +0100 as excerpted:

> I have created mentioned file and run emerge, but I've got
> 
> $ sudo emerge -av @critical
> !!! '@critical' is not a valid package atom. !!! Please check ebuild(5)
> for full details
> 
> And I have no idea why. Also, I'm using portage 2.1.7.1. I guess this is
> new feature in 2.2?

Yes.  Sets were left for 2.2, as the implementation wasn't quite ready 
for 2.1 stability.  (As I understand it, there's multiple set 
implementations, and before sets become available as in-tree kde install 
options, for instance, they needed some reconciliation and possible PMS/
EAPI approval.)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman