On Thursday 22 Dec 2011 19:07:02 Alan McKinnon wrote:
> On Thu, 22 Dec 2011 19:58:32 +0100
> 
> Jarry <mr.jarry@gmail.com> wrote:
> > On 22-Dec-11 19:38, Mark Knecht wrote:
> > >> Why does portage want to unmerge sys-apps/less when it is
> > >> a part of system?
> > > 
> > > I didn't like it either so I've been adding it to
> > > /var/lib/portage/world just to stop it. I've seen this on one
> > > machine or another for 6 months to a year I think.
> > 
> > Some time ago emerge wanted to uninstall "nano" - part of system.
> > Now "less". I just tried to update one more comp, and guess what?
> > 
> > # emerge --depclean
> > Calculating dependencies... done!
> > 
> >  >>> Calculating removal order...
> > 
> > !!! 'sys-fs/udev' (virtual/dev-manager) is part of your system
> > profile. !!! Unmerging it may be damaging to your system.
> > 
> >  >>> Waiting 10 seconds before starting...
> >  >>> (Control-C to abort)...
> > 
> > Press Ctrl-C to Stop in:  10 9
> > 
> > LOL, what the hell is going on? Porgage went crazy or what?
> 
> This has been in unstable for many months now. Basically there's now a
> virtual for $EDITOR and $PAGER so you can pick the one you want. If you
> don't pick one, portage will take the default and --depclean is likely
> to remove the others that are not in world.
> 
> This was all discussed to death months ago :-)
> 
> Just add your editor and pager of choice to world and continue as
> normal. It's not a big issue - you already know you want less and have
> no intention of removing it, so just add it like any other package.

$ cat /etc/env.d/99editor 
# Configuration file for eselect
# This file has been automatically generated.
EDITOR="/usr/bin/vi"

You could replace for nano, or indeed add both in world file.  Ditto for pager 
(more/less/most, etc).

I'm not sure about the udev message though.
-- 
Regards,
Mick