Re: [gentoo-user] This nite's switch to "full multilib"

[Rich Freeman <rich0@gentoo.org>]

On Mon, Mar 30, 2015 at 6:02 AM, Stefan G. Weichinger <lists@xunil.at> wrote:
>
> OK, then so why do I have to edit files to tell the system to USE this
> and that after the system tells me it needs that ... ?
>
> Why isn't this taken care of within portage itself?
>
> I don't *want* to decide 32bit or not ... (I like that I *can* ...)
>

This goes way beyond 32-bit.

The way things work in Gentoo right now is that portage can decide to
install a package at any time without any config file changes (unless
it is keyword/package masked).  However, it can't change the USE
configuration of a package unless this ends up in a config file.

In a sense I think giving portage more freedom to do this would be
better.  It does increase the likelihood of blockers, but we already
deal with those for package blocks.  It would also mean that a proper
depclean might actually involve package rebuilds (unless we make
depclean just remove stuff, and an emerge -N rebuild stuff).

I'm trying to think of what the downside is to just letting portage
set the flags however seems best unless a flag is explicitly set or
unset in configuration.  I can't think of any issues offhand - I think
that most of the work that needs to be done by emerge to calculate
deps needs to be done anyway.  Obviously it would take effort to do.

I ended up with 800 lines being added to my package.use, which now
constitutes 2/3rds of the file.  Granted, most of those are comments.

Some of the comments are also less than ideal, like:
# required by media-libs/libgphoto2-2.5.7
# required by kde-base/kamera-4.14.3
# required by kde-base/kdegraphics-meta-4.14.3
# required by kde-base/kde-meta-4.14.3
# required by @selected
# required by @world (argument)
>=virtual/libusb-1-r1 abi_x86_32

This tends to imply that kde-meta needs 32-bit libusb.  I suspect that
some other package does need 32-bit libgphoto2, which then needs
32-bit libusb, but kde-meta shows up in the comment instead.

The packages that gave me the most trouble were wine and steam.  I
don't think there were any problems with them - they just pull in a
lot of 32-bit deps.

-- 
Rich