if we execute the qt app directly, the qt.conf under same directory is loaded correctly.

usr/bin/app
usr/bin/qt.conf
usr/lib/ld-linux.so

but if we execute the app using ld-linux.so, the qt.conf is not loaded, which result in error for not found plugins/qml.

<some_dir>/ld-linux.so app

we must place the qt.conf under same directory as the ld-linux.so.