qt6: cmake: add export QT_SELECT=qt6

[dakejahl]

If you have multiple versions of Qt installed you need to set this, cmake will find Qt5 first.

[DonLakeFlyer]

But what version of Qt6 does that pick? For me I need CMAKE_PREFIX_PATH to point right to the one I want to use.

[HTRamsey]

We need to add to the instructions that you should use /Qt/6.8.2/gcc_64/bin/qt-cmake (adjust based on your path & platform)

[DonLakeFlyer]

Yeah, that probably makes sense as the best option

[dakejahl]

so what's the best way to do this? Can we add the default path to cmake and error if it doesn't find the exact version we want? And a user could override with an env var if they want to specify a different version

[DonLakeFlyer]

If you want to use cmake directly instead of say just using Qt Creator which will get you the right thing, then I think you are kinda on your own to set up an alias to qt-cmake using whatever OS mechanism you have available. Gonna be too long winded to explain something for every OS. But I'd hope if you want to go this route you kinda know what you are doing already and can handle that. Otherwise you should be using Qt Creator.