[Development] Switch the main "Qt Build System"

[Joerg Bornemann]

On 6/9/20 7:22 AM, Bogdan Vatra via Development wrote:

> - is it possible to cross compile Qt in one go (just like we do with qmake)?

Assuming you're talking about the multi-ABI Android build you've added 
to Qt5. This is not yet implemented, but certainly possible with the 
Ninja Multi-Config generator that has been added to CMake 3.17 [1].

> - if you'll not support/trash all .pro/.pri files how we'll push fixes for 5.15
> branch ? Because right now we can't push fixes directly to 5.15. branch and all
> the fixes must go trough dev branch first.

All changes that do not apply to Qt6 must go to 5.15.
It's not true that we can't push fixes to 5.15 anymore.


BR,

Joerg

[1] https://blog.kitware.com/multi-config-ninja-generator-in-cmake-3-17/