Building the official minimal Qt VTK example with Qt6 uses Qt5 instead

Support
3

I can do that, the following entries are located inthe CMakeCache.txt:


//The directory containing a CMake configuration file for Qt5Core.
Qt5Core_DIR:PATH=/usr/lib/x86_64-linux-gnu/cmake/Qt5Core

//The directory containing a CMake configuration file for Qt5Gui.
Qt5Gui_DIR:PATH=/usr/lib/x86_64-linux-gnu/cmake/Qt5Gui

//The directory containing a CMake configuration file for Qt5OpenGL.
Qt5OpenGL_DIR:PATH=/usr/lib/x86_64-linux-gnu/cmake/Qt5OpenGL

//The directory containing a CMake configuration file for Qt5Widgets.
Qt5Widgets_DIR:PATH=/usr/lib/x86_64-linux-gnu/cmake/Qt5Widgets

//The directory containing a CMake configuration file for Qt5.
Qt5_DIR:PATH=/usr/lib/x86_64-linux-gnu/cmake/Qt5

I can change these to point to Qt6 instead, but if I run cmake .. or make again, it will just reset the CMakeCache file. So unfortunately, the problem still exists. :-\
Is there a more permanent way to tell my environment to provide Qt6 instead?