Re: [gentoo-dev] Re: useflag policies

[Sergey Popov]

11.08.2015 15:30, Michael Palimaka пишет:
> On 11/08/15 20:10, Sergey Popov wrote:
>> Err, i have read the whole thread and still does not get a point, why i
>> am wrong.
>
> You clearly have not. The reasoning behind Qt team's policy is described
> on the page and has been reiterated on this list. You are undermining
> what little confidence there is in the QA team by making decisions with
> no consultation about problems you do not understand.
>
>> It's old battle like we have beforce with "gtk" meaning "any versions of
>> GTK flag". This behaviour should be killed with fire.
>>
>> Let's me reiterate some of the cases:
>>
>> 1. Package can be build without Qt GUI at all, but either Qt4 or Qt5 can
>> be chosen, but not both.
>>
>> Fix this with REQUIRED_USE, do not enable any of Qt flags by default
>
> Problem: this requires manual intervention if the user has both qt4 and
> qt5 USE flags enabled.
>

User choice of using USE flags is NOT a problem

>>
>> 2. Package can not be build without Qt GUI - either Qt4 or Qt5 is
>> required, but not both
>>
>> Same thing here, different REQUIRED_USE operator. But - enable one of
>> the flags by default to ease life of users.
>
> Problem: this requires manual intervention if the user has both qt4 and
> qt5 USE flags enabled.

Same here

>>
>> 3. Package can be build with Qt4 or Qt5 or both AT THE SAME TIME(if such
>> package even exists?)
>>
>> Do not use REQUIRED_USE here, not needed.
>>
>> Now, please tell me, where am i wrong?
>>
>
> The problem is manual intervention is required if the user has both qt4
> and qt5 USE flags enabled - and this is a common configuration. It is
> not acceptable to make a user manually add numerous package.use entries
> when all they want to do is install KDE.

And here

> I agree Qt's policy is not a perfect solution, but in the absence of
> some feature allowing a preference to be set when there is a conflict
> it's the best we've got.
>

If you want to go this way, then please provide helper functions in
eclasses to set dependencies properly for all common use cases. That
will ease life both of developers and users.

Leaving constructing of dependencies to developers in all cases will
cause only pain in your solution.

Look at the example with berkdb/gdbm, that i have posted recently.

If both of flags are not set - we stick to default.
Should this be set in EVERY ebuild explicitly?

Maybe provide some sugar like $(qt_use_default qtgui 5), where
qt_use_default is the name of function, qtgui is the package and 5 is
the slot for default choice, where either BOTH of flags(qt4, qt5) are
enabled or disabled

-- 
Best regards, Sergey Popov
Gentoo developer
Gentoo Desktop Effects project lead
Gentoo Quality Assurance project lead
Gentoo Proxy maintainers project lead