Debian (I might as well say "we", this is the beauty of it) is about to release Debian 12 aka Bookworm. Let's take a quick look at what is new in Debian Qt land.
Bookworm has Qt 5.15.8, which is nothing but great news. KDE will be switching to Qt 6 sooner than later and Qt 5 has been a fun ride, but Dmitry Shachnev and I needed a break, or at very least not handling two Qt versions. But in the end I need to be fair: you REALLY need to thank Dmitry for Qt 5. He has been the man power behind it in 99.5% of the cases.
This will be the first Debian release to have official Qt 6 packages. NOTHING would have happened if it weren't for Patrick "Delta-One" Franz standing up to maintain it. BIG kudos to him!
Well, there is a "little lie" in the paragraph above. Thanks to The Qt Company and ICS the current Qt 6 version, 6.4.2, is also available as Bullseye's backports. The Qt Company really also helped us here by providing us almost-to-be-released tarballs of Qt 6.4.2 so we were able to push them to unstable and do a transition in time for freeze, thanks a lot for that!
So, what is the Qt 6 state?
At the binary side all but OpenGL ES support should be there. Sadly this was discovered too late in the release process and we still might need help maintaining it (read the link to know why!).
We are still not building the documentation. Properly building the whole documentation, as with Qt 5, would require all the Qt submodules' source code in one place, which we can't (easily?) do in Debian. So building the doc means hacking the build system and getting semi-linked documentation, much like with Qt 5. Now if you think you have an idea to solve this... we are happy to hear from you!
Another great thing to know about Qt 6 is that, thanks to Helmut Grohne, pure Qt 6 applications should be able to cross compile. Applications using multi-arch enabled libraries ought to work too. Even more, many Qt submodules themselves should also cross compile! Not all of them, as we missed some patches in time, but hey, if you need to cross compile Qt, you surely can apply them yourselves!
And finally tests, unit tests. In Qt 5 we had some of those, but none yet in Qt 6. This is one of the areas I would love to be able to put time... but time is scarce.
In my point of view the Debian 13 "Trixie" development cycle will see Qt 5 diminishing it's usage and Qt 6 becoming the major Qt version used, but from the Qt 4 experience I do not expect Qt 5 being dropped during this release cycle... let's see what the future brings us.
While I mentioned Dmitry and Patrick many more people helped us reach this place. I personally want to thank the people behind the KDE software, both upstream and, of course, the Debian maintainers. You should be thankful with them too, many hours of effort go into this.
And thanks to you our dear users. We are normally overflowed with what we have in our hands and might not be up to the task sometimes, but hey, you are part of the reason we are doing this!