I went the scratchbox route. I'm too tired to write any details.

But it seems qt-components (even the QtQuick 2 branch) needs modifying before it can work on Qt5. The plugin loading has been changed, so relating to harmattan development at least the meego subdirectories plugins have to be modified like this:

http://qt.gitorious.org/qt/qtbase/co...25ac404e303c5d

Writing this here if someone wants to take the ball and run with it .