What Build System Should Qt 6 Use?

While developers have begun discussing plans for Qt 6.0 with plans to ship this upgraded tool-kit in 2020, one of the unanswered questions is over what build system should Qt 6 be using.

Up to now there's been a lot of pointing at Qbs as the new build system for Qt6. Qbs dates back to the Nokia days but has been seeing a number of improvements in recent times under the assumption it could replace Qmake as the default build system of Qt6. Qbs is designed to be easier to use than Qmake, which goes back to the original Trolltech days, while having the potential to be more powerful and offer much more flexibility.

Without voicing a preference as to the Qt 6 build system, Intel open-source developer Thiago Macieira and a longtime upstream Qt developer, has shared what he feels should be some requirements of whatever build system is selected.

Among the preferences he has about the Qt6 build system's capabilities are any build requirements being widely deployed across all major/tier-one Linux distributions, ideally having the build support on MSVC and FreeBSD too, it must be "easily" compiled from source, the build system must have a proven track record, offer community support, and must have already been proven for a project with similar complexity to Qt's base.

More details on Thiago's opinions via this new Qt list thread. In a follow-up message, Thiago clarified he isn't trying to rule out Qbs and hasn't even really looked at it, but is trying to lay the firm requirements for what is needed for Qt's future build system.