Currently QT_DISABLE_DEPRECATED_BEFORE value is hardcoded in qtbase/cmake/QtFlagHandlingHelpers.cmake.

However when I manually change the value to something more recent in

function(qt_internal_library_deprecation_level result)

I notice that the unit-tests do not get the new value.

If something is guarded by

#if QT_DEPRECATED_SINCE(6, 0)

macro, it is still compiled, thus generating compiler errors.