Beta 1 binary package has only forwarding pri files under mkspecs/modules. It seems that this happens because qtbase.pro installs every folder that exists under mkspecs at the time the qmake is run, which on clean build means there will only ne mkspecs/modules but no mkspecs/modules-inst. This installation will overwrite the non-forwarded versions of module .pri files installed by each module with forwarded versions.

There is "mkspecs.files -= $$PWD/mkspecs/modules" line in qtbase.pro, but that doesn't seem to work, possibly because drive letter case is different for this path in mkspecs.files.