Sunsetting Qt 5

[christoph at cullmann.io]

On 2024-11-30 11:51, Albert Astals Cid wrote:
> El dissabte, 30 de novembre del 2024, a les 4:57:10 (Hora estàndard del 
> Centre
> d’Europa), Ben Cooksley va escriure:
>> HI all,
>> 
>> This past week or so i've been dealing with a number of issues 
>> relating to
>> a handful of still Qt 5 based projects trying to make use of updated
>> dependencies. These issues have revealed that the level of support for 
>> Qt 5
>> as a platform in general is now subject to a significant degree of 
>> bit-rot.
>> As such, we need to set a point at which we consider Qt 5 to no longer 
>> be
>> supported.
>> 
>> To start I would like to remove support for all CD builds (Windows,
>> Appimage, macOS) as well as CI support for Windows. There is already a
>> general view in Craft that Qt 5 is unmaintained and this removal 
>> simply
>> reflects that.
> 
> If the Craft maintainers don't want to maintain Qt5 and no one steps up 
> I
> guess that's understandable.
> 
>> 
>> Additionally, several recent attempts to update our Windows Qt 5.15 
>> images,
>> based on MSVC 2019, have all failed due to various different changes 
>> (with
>> the build of MPFR breaking for reasons unknown - likely MSys2 updates 
>> - and
>> QXMPP failing to build yet again....) which is not a tenable position 
>> for a
>> "CI supported" platform.
>> 
>> That removal is proposed to be essentially immediately (ie. now).
>> 
>> Subsequent to that I would also like to forbid any further feature 
>> releases
>> to be made of Qt 5 software following the end of this calendar year, 
>> to
>> clearly signal to the involved developers that they need to work on 
>> getting
>> a Qt 6 release out. Patch releases to resolve bugs and security issues
>> could continue to be made for a period of 6 more months at most.
> 
> This is not acceptable.
> 
> Qt 5.0 was released in December 2012
> 
> We introduced KDE Frameworks 5 in July 2014
> https://kde.org/announcements/frameworks/5/5.0.0/
> 
> We stopped accepting kdelibs4 based apps in the 
> "was-KDE-Gears-back-then" in
> December 2017
> https://community.kde.org/Schedules/Applications/17.12_Release_Schedule
> 
> 
> 
> Qt 6.0 was released in December 2020
> 
> We introduced KDE Frameworks 6 in February 2024
> 
> If we do the diff against our KF6 release we should accept KF5 apps in 
> KDE
> Gear at least until 2027, if you count since Qt relase we need to 
> accept them
> until end of 2025.
> 
> Giving 1 month of heads up is not ok.

One month is not long enough.

I would propose to set some 25.xx deadline for that, like one of the 
Gear releases
there.

But just to be sure, about how many applications on invent do we talk.

Greetings
Christoph


> 
> Cheers,
>   Albert
> 
>> 
>> Any application that does not have a port underway as at the point 
>> where
>> feature releases become forbidden is proposed to be archived as
>> unmaintained at that time, with the same fate befalling applications 
>> that
>> have an unreleased port branch on 1 July 2025.
>> 
>> Should at any point post-31 December 2024 there become issues that 
>> make Qt
>> 5 CI unsustainable for the remaining platforms (Linux and FreeBSD) 
>> then we
>> would discontinue CI for them at that time as well with minimal notice
>> being given in advance.
>> 
>> Note that while this may seem a little "over the top" it is necessary 
>> to
>> reduce the maintenance burden and cost of keeping Qt 5 alive (for an 
>> ever
>> decreasing number of applications) on the maintainers of central
>> infrastructure (such as myself).
>> 
>> Regards,
>> Ben