Qt6 prebuilt tarballs for REG-Linux
Source code and patches available at :
https://github.com/REG-Linux/REG-Linux/
https://github.com/REG-Linux/buildroot/
Especially have a look at : https://github.com/REG-Linux/buildroot/tree/br2-external/package/qt6