[Interest] How to use Qt6::qmake ?

[Marius Kittler]

Hi,

Qt's CMake modules should already make most paths available. I came up with 
the following approach to support Qt 5 and Qt 6: https://github.com/Martchus/
qtutilities/blob/5960c215586cf0ca777a511c6f0830c1c63ddaa8/cmake/modules/
QtLinkage.cmake#L124

It works at least for QT_INSTALL_TRANSLATIONS. Maybe it needed to be tweaked 
for other variables.

This function also shows how to get the location of the qmake binary if you 
really need it after all.

I'd also suggest to use the CMake modules Qt provides for using Linguist. This 
has already worked with Qt 5 and continues to work with Qt 6. When cross-
compiling you currently need a workaround, though: https://github.com/
Martchus/qtutilities/blob/5960c215586cf0ca777a511c6f0830c1c63ddaa8/cmake/
modules/QtConfig.cmake#L303