cmake does not find QtQuick even if it's installed

I installed Qt 6.2.0 with the online installer and selected most of the module for Desktop development.I get this strange message:

/home/user/Qt/Examples/Qt-6.2.0/multimedia/video/mediaplayer/CMakeLists.txt:28: error: Found package configuration file: /home/user/Qt/6.2.0/gcc_64/lib/cmake/Qt6/Qt6Config.cmake but it set Qt6_FOUND to FALSE so package "Qt6" is considered to be NOT FOUND.  Reason given by package: Failed to find Qt component "Quick". Expected Config file at "/home/user/Qt/6.2.0/gcc_64/lib/cmake/Qt6Quick/Qt6QuickConfig.cmake" exists

English is not my primary language, and I'm not sure what the last sentence really means:

"Expected Config file at <path> exists"

Actually the file exists:

$ ls /home/user/Qt/6.2.0/gcc_64/lib/cmake/Qt6Quick/Qt6QuickConfig.cmake /home/user/Qt/6.2.0/gcc_64/lib/cmake/Qt6Quick/Qt6QuickConfig.cmake

I don't understand why it don't find QtQuick and then I don't know how to fix it...