Ok, I got mumble compiled on builder. Package is not optified or tested in any way. Because of issue of qt4 and PR1.2 package is not installable state.

*Builder uses PR1.2 and there libqt4-core = qt4.6
*Device uses PR1.1 and there libqt4-core = qt4.5 and libqt4-maemo5-core = qt4.6.

So I think it is best to wait PR1.2