I installed Qt 6.1.0 on my openSUSE 15.3 installation. When I compile an application which has QFIle included I get the following compiler error:

fatal error: filesystem: No such file or directory
#include <filesystem>

I tried to add:

CONFIG += c++17

or

QMAKE_CXXFLAGS += -std=c++1z

to my qmake file, but this didn't help.

Do I have to install any additional packages, or how can I solve this? The same application compiled perfectly on openSUSE 15.2

Thanks for your help