Created project with qbs - compiler complain about qmake errors

I created an empty Quick project and selected the "qbs' option.
Ran the program it worked as expected.

When I looked for errors I found this:
Project ERROR: You need to set the ANDROID_NDK_ROOT environment variable to point to your Android NDK.
Could not read qmake configuration file /home/leemke/Qt/5.15.0/android/mkspecs/android-clang/qmake.conf.
[qbs] Build graph does not yet exist for configuration 'Debug_Desktop_038b678e9426a45b'. Starting from scratch.
[qbs] Setting up Qt at '/home/leemke/Qt/5.15.0/gcc_64/bin/qmake'...
[qbs] Qt was set up successfully.
[qbs] Build done for configuration Debug_Desktop_038b678e9426a45b.
[qbs] Build done for configuration Debug_Desktop_038b678e9426a45b.
Project ERROR: You need to set the ANDROID_NDK_ROOT environment variable to point to your Android NDK.
Could not read qmake configuration file /home/leemke/Qt/5.15.0/android/mkspecs/android-clang/qmake.conf.

I was able to select Andriod as a platform, but Android SDK is not installed.
I started from a vainilla system (delete beta linux and reinstall). I did install
some extra packages as my base system: tilex, python, jdk, aptitude, other basic support
packages. And then I installed Qt. with the 5.15.x? installer from your website.