Re: [gentoo-dev] useflag policies

[Davide Pesavento <pesa@gentoo.org>]

On Mon, Aug 3, 2015 at 8:59 PM, Ben de Groot <yngwin@gentoo.org> wrote:
> On 4 August 2015 at 04:20, Rich Freeman <rich0@gentoo.org> wrote:
>> [...]
>> Gentoo should be the best of both worlds.  We should give users the
>> power to tweak things, but we shouldn't force them to play with config
>> files all day long just to have a functional system.  If users want to
>> care we let them care instead of telling them "don't touch" like most
>> other distros, but if they don't care we still provide reasonable
>> defaults.
>
> And that is exactly what we do. The kde profile enables qt4, the
> plasma profile enables qt5, the other profiles have no qt* useflags
> enabled. These are reasonable defaults.
>

As tetromino pointed out, this is very far from the real current situation.

> Of course some users will proceed to enable both qt4 and qt5 globally
> in their make.conf, but I don't think it is unreasonable to expect
> them to then deal with adding exceptions to package.use for those
> packages where exactly-one-of is required.
>
> In my opinion, this is the way Gentoo has always worked, and we should
> simply recommend users to only set one of the qt* useflags as globally
> enabled, if they want to prevent such micro-management. Hiding the qt4
> option is in my opinion the wrong solution around people complaining
> after they have consciously enabled both flags.
>
> If this is not acceptable (or "absolutely unusable" as one dev put
> it), then we need a proper solution, which a) will not hide the qt4
> option, and b) will prevent triggering required_use blockage by
> choosing qt5 over qt4 in case both are enabled, while c) informing the
> user about this. This probably requires new eclass or even EAPI
> functionality.
>

Please go ahead and design and implement such functionality (a sort of
REQUIRED_USE defaults). In the meantime, we will apply the policies
written in the Qt project wiki page.

> In the meantime, we should stick with the policies adopted at the qt3
> to qt4 transition (explicit versioned useflags) and let the user deal
> with per-package management if they enable both flags.
>

We didn't have REQUIRED_USE at the time of the qt3->qt4 transition, so
this point is completely moot.