[Development] Build system for Qt 6

[Richard Weickelt]

> Qbs is something that has been developed almost exclusively by The Qt
> Company. As such, TQtC had to also look at it from a business perspective
> and how it fits into the larger picture of making Qt successful. To make
> a long story short, while Qbs is pretty cool and interesting technology,
> it doesn’t really help us expand the Qt ecosystem and usage.

Qbs has made the development of multi-platform applications with multiple
libraries a breeze for me. Even projects that contain firmware for different
target architectures in addition to a Qt application are no problem at all
with Qbs. Thanks to Qbs, I can focus on code and not on the build system. I
achieve more in less time.

I always thought that Qbs was a great example for using QML.

> To make Qbs really successful would require a rather large effort and
> investment in promoting it towards the larger C++ ecosystem as a new
> build tool. At the same time it has to be an open source product to stand
> any chance in the market. Together this makes it challenging for TQtC to
> see how to recover that investment. Thus this investment would be at the
> expense of other things we’d like to do, like improving our IDE, working
> on rearchitecting and cleaning up our core frameworks for Qt 6 or the
> design tooling we are currently investing into. The Qt Company believes
> that those other investments are more important for the future of Qt than
> our choice of build tool.

It seems that Qbs never got much traction within the Qt Company either.
Outside the regular blog posts, I don't see any attempt to promote Qbs
anywhere. Correct me if I'm wrong. I may have noticed that Jake Petroules
did his best to get the word out, but I guess that was his private mission
rather than his official role in the Qt Company. What I can't complain about
is the unprecedented dedication and professionalism of Christian, Jörg and
Jake on this project. Also all support questions were answered in lightning
speed.

> As such, we were left with the question on whether we need Qbs as the
> build system for Qt 6 or whether cmake (as the other alternative) would
> be up to the task.
> [..]
> Given that we are confident we can build Qt 6 with cmake, I believe that
> it makes most sense to follow down that route. In case you’re interested,
> you can have a look at the cmake prototype code for qtbase on Gerrit in
> the wip/cmake branch. Please also let us know if you’re interested in
> helping with the effort of porting Qt’s build system over to cmake.
> 
> We have been developing Qbs over the last years, and as such are
> committed to it for some more time. We are planning on another feature
> release in the first quarter of next year and will support it in Qt
> Creator for at least another year. Qbs is open source and if someone
> wants to take over and develop it further let us know as well. I’d also
> like to use this place to thank Christian and Jörg for all their great
> work on Qbs  (and of course also anybody else who contributed to it).

How can we leverage from the next half year to smoothly turn Qbs into a
community-owned OS project? Does anybody know a positive role-model for this?

I don't want to miss out on the productivity gains I've made with Qbs, but
on the other hand I have very little free time. However, I would voluntarily
contribute to the documentation of Qbs.

Richard