[gentoo-dev] Re: Re: Re: News item: World file handling changes in Portage-2.2

[Steve Long]

Dale wrote:

> Holger Hoffstaette wrote:
>> On Wed, 10 Sep 2008 11:38:56 +0100, Mike Auty wrote:
>>> Marius Mauch wrote:
>>>
>>>> Maybe the best solution is to drop the non-prefixed versions of 'world'
>>>> and 'system' completely ....
>>>>
>>> Deprecating the old syntax sounds like a sensible action to get people
>>> shifted onto the new system.  I imagine it would work very similarly to
>>> "emerge info" at the moment?
>>>
>> Speaking purely as a user, from a usability perspective it's a horrible
>> idea. Don't make me remember special things. To me there is no
>> discernible difference between "system" and "@system", except that I have
>> to remember to prefix the latter over and over again. Different things
>> need different names.
Well you might well have other sets, like @kde4 or anything you like, which
would be up to you to maintain as a user.

>> Doesn't portage have more pressing problems? In the
>> last 6 years of using Gentoo I cannot remember a single instance where
>> the difference between system and world even mattered to me from an
>> operational point of view.
>>
I've seen it most for new installs, where the user might use 'emerge -e
system' to get the base stuff built for their specific CPU, followed
by 'emerge -uDN world'. For major gcc upgrades, it's common to want to
use 'emerge -e system' first followed by 'emerge -e (world - system)' which
is an approach emwrap[1] pioneered.

Personally I don't see much point to the first -e system, since major gcc
upgrades are really only a breakage issue for C++ apps (paludis has in the
past stopped working after a gcc upgrade of this sort, which can be an
issue if there is no way to use another package manager to get it rebuilt,
which is the recommended config.)

update[2] does the recommended (based on various user posts, can be tweaked
ofc) order for any toolchain packages (extended def'n if $compiler is in
the list, including things like automake if there's a new version) which
appear for any emptyTree build, prior to the rest of the list. This
makes 'update -e world' pretty good for gcc upgrades (it'll skip a major
gcc upgrade in other circumstances, so that your system isn't left
inconsistent.)

> Also speaking as a user, I confuse pretty easily and you can ask anyone
> on gentoo-user about that.  However, I see the difference between
> @system and system.  The same for world or at least a good idea anyway.
>
Afaict there is no difference between system and @system. The question is
whether world and @world can coexist with different meanings, provided the
user hasn't run 'emerge system' (or @system) which atm makes the @system
set part of @world. (Confused? You will be ;) This is useful for user- or
profile-defined sets, eg for the earlier example, emerge @kde4 would make
the @kde4 set part of @world (by reference; @kde4 is put into world, not
the individual packages from it, so it can be maintained as a separate
list.)

A user wishing to avoid @system being part of @world can set
world-candidate=false in /etc/portage/sets.conf, to keep using @system and
@world separately. (see /usr/share/portage/config/sets.conf for examples.)
 
> I have to also say that I like being able to type in emerge -uvDN world
> and letting my system upgrade everything that needs upgrading.  It's
> simple, easy and not so much typing.

> I can somewhat understand the need
> for @system and @world but think both can live together pretty well.

Yeah I agree; I don't think every user is going to be interested in sets,
and I see it as a minor, encapsulated, special-case in code terms, whereas
it has pretty major impact on end-users (and will cause support hassle.)

As soon as you type @foo you know you're in set-land.

> I do think there should be some sort of notice for those users that do
> not follow -dev, -user and/or the forums tho.  That has been a issue for
> a long time.  There does not seem to be a clear cut way to inform all
> Gentoo users except during a emerge.
Yeah although the news item thing did get accepted as a GLEP, and afaik the
package managers support them, I've never actually seen a news item in the
console. Maybe I'm doing something wrong again..

> Thing is, emerge -uvDN world will do the same as it always has from my
understanding.
>
Well it'll tell you that usage is deprecated, and until you emerge system
(or @system) it won't be considering those packages as part of world. (I
believe it will be added automatically on upgrade from 2.1 to 2.2 for
stable.) Once you do, it'll require a bit more to do an emerge -e @system
&& emerge -e @world. If you are keeping them separate, you'll need
emerge -uDN @system @world, aiui.

Hence the desire to keep 'world' meaning what it always has, irrespective of
the sets.conf.

As I said before, I consider this minor tweaking to cli usage for major new
functionality, which I think is really cool stuff. Whichever way the
portage devs decide to go, kudos to them for what they've come up with.

[1] http://forums.gentoo.org/viewtopic-t-282474.html
[2] http://forums.gentoo.org/viewtopic-t-546828.html