RFC: Switching to min Qt version 5.14 for KF on December 14th

[David Faure]

On jeudi 17 décembre 2020 00:20:41 CET Friedrich W. H. Kossebau wrote:
> Hi,
> 
> Am Samstag, 12. Dezember 2020, 22:25:32 CET schrieb David Faure:
> > Just a data point on this discussion. Every time we raise the min Qt
> > version, we make life easier for KDE developers, and harder for others who
> > might be thinking of integrating a framework into their project.
> > 
> > Just today I tried using a KF5 library to extend a single plugin in an
> > existing webserver (which I don't control, and which is mostly written in
> > python) [1]. That server is entirely set up with a docker environment on
> > top of... debian buster, which has Qt 5.11.3.
> > Fail.
> > I'm going to have to apply a patch to the KF5 library as part of the
> > Dockerfile, to port it back to Qt 5.11. No way I can convince them to
> > change the base distribution, all I'll get as a reply is to port away
> > from QtCore.
> > 
> > Obviously the 5.11 ship has sailed by now, and I know we can't support old
> > versions forever, but this kind of experience makes me very wary of
> > raising
> > requirements too fast.
> 
> I am reading an objection to the proposed bump in these words, am I correct
> in doing that? 

Objection is a strong word. I am not blocking the proposed bump, I am merely
realizing that the balance between contributor convenience and 
user-convenience (where the user is a developer) is difficult to achieve, 
after this (anecdotal indeed) evidence.

(And yes I needed something very recent, but it wasn't actually a framework,
it was another Qt/KDE library, KOpeningHours. I thought it was still 
illustrative of what one might encounter when trying to use a KDE framework 
outside its usual box of "the rest of the KDE software".)

> Though please those who want to support Qt 5.13 for some more time, consider
> adding support for KDE CI then. It leaves a bad feeling in my stomach that
> KF 5.77+ seems effectively for Qt 5.13 with a sticker "Good Luck!" right
> now. I fear that lowers the image with (potential) KF consumers, it does at
> least with me for other projects.
> I (and possibly many other KF contributors) have no way to test against Qt
> 5.13, so might introduce regressions/break things in the future, which feels
> bad :/

Right. That's a reason to fix something indeed, but there are still two ways 
to fix that, if it was the only reason : either raise min req to Qt 5.14, or 
ask for a Qt 5.13 CI.

In general I might have asked for a more conservative approach; but currently
anything we do to help with preparing the Qt 6 migration is a good thing,
and having one less Qt version to support helps with that.

So, in those exceptional circumstances, I'm in favour, go for it.

-- 
David Faure, faure at kde.org, http://www.davidfaure.fr
Working on KDE Frameworks 5