Linux CMake will not use version in /opt

[Musmuris]

Hi,
Developing on Linux (actually WSL Ubuntu 22.04). I have the Ubuntu QT (6.2) packages installed (to /usr/lib) but I also used the installer to get v6.7.0 at /opt/Qt.

I cannot seem to persuade CMake to use the version at /opt!

My command line is this
cmake -DCMAKE_PREFIX_PATH=/opt/Qt/6.7.0/gcc_x64/lib/cmake/Qt6 -DQt6_DIR:PATH=/opt/Qt/6.7.0/gcc_x64/lib/cmake/Qt6 -S . -b linux_build

but the cache and build still use /usr/lib version. Any hints?

[Musmuris]

Ok - I have no idea where I got that "x" in gcc_x64 - it's just gcc_64

And the correct incantation seems to be

cmake -DCMAKE_PREFIX_PATH:PATH=/opt/Qt/6.7.0/gcc_64 -S . -B linux_debug

UPDATE:
Additionally I needed

sudo apt install libglx-dev libg1-mesa-dev

Otherwise it mysteriously failed finding QtGui

[Musmuris]

It was in typing the original question that I thought "what does QtCreator do"? - and got the command line from there