Re: [gentoo-dev] useflag policies

[Patrick Lauer]

On Monday 03 August 2015 00:34:51 Ben de Groot wrote:
> Recently some team members of the Qt project have adopted these ebuild
> policies: https://wiki.gentoo.org/wiki/Project:Qt/Policies
>
> I have an issue with the policy adopted under "Requires one of two Qt
> versions". In my opinion, in the case where a package offers a choice
> between qt4 or qt5, we should express this in explicit useflags and a
> REQUIRED_USE="^^ ( qt4 qt5 )". This offers the user the clearest choice.

Since qt4 and qt5 are both relatively 'heavy' dependencies and quite different 
in many ways (including differences in default styles) many users will want to 
stick with only one of those.

The gtk 'solution' forced some ugly things like masking gtk+:3, gconf:3, ... 
and then selecting packages based on specific -r200 / -r300 revisions. So much 
work to avoid regressing into gtk3!

(Which is especially frustrating because *dbus* has wrong dependencies just so 
that gtk/gnome apps using dconf can save config ... )
>
> Other developers state that users are not interested in such implementation
> details, or that forced choice through REQUIRED_USE is too much of a
> hassle. This results in current ebuilds such as quassel to not make it
> clear that qt4 is an option.

I find setting USE="qt4 -qt5" a lot more obvious than having USE="qt" (why not 
USE="X" ?) which then does different things based on another useflag, 
sometimes. Maybe. It's horribly inconsistent and even might change result over 
time, which is not very user-friendly.
>
> This goes against the principle of least surprise, as well as against QA
> recommendations. I would like to hear specifically from QA about how we
> should proceed, but comments from the wider developer community are also
> welcome.

I would prefer having qt4 and qt5 useflags independent, and no generic qt 
useflag.