[Development] Did we have to remove cmake's qt5_use_modules?

[Kai Koehne]

> -----Original Message-----
> From: Development [mailto:development-bounces+kai.koehne=qt.io at qt-
> [...]
> The Qt promise is to maintain not only source code, but upward binary
> compatibility until a major version.
> 
> When said promise is broken immediately after a major version release, as it
> was the case just after Qt5 release to fix an oversight, this is not harmful.
> 
> When it happens years after release, and this is indeed the case here for
> deprecated modules, and was also the case with the switch away from Webkit,
> it can be a major problem not just for distributions, but for many projects that
> depend on it and did not budget a major change.

Overall I do think we're on the very conservative side when it comes to removing things. We're still dragging modules along that were deprecated in Qt 5.0 already ... Qt WebKit was somewhat special in that a) it was quite big, and b) it's often used in a security critical setup. But eventually Konstantin volunteered to revive qtwebkit, so I guess it's ok now?

> To maintain source and binary compatibility, deprecated modules should not
> be removed until QT6. I do not even understand why there is a debate about
> this.

Note that the case in question is about deprecated functionality in the build system, not about removing any Qt modules. So the BC guarantee doesn't apply here. 

Kai