Using a Qt 5.6 beta version build on windows with msvc ( 12 ),
the generated qbs profile (usign qbs setup-qt), libFilePath[Release|Debug] contains
"Qt5XXX.lib".lib" instead of "Qt5XXX.lib"
Qt5Core.prl contains "QMAKE_PRL_TARGET = Qt5Core.lib" wich is probably the root cause of the problem as a second .lib is unconditionally added as per http://code.qt.io/cgit/qt-labs/qbs.git/tree/src/lib/qtprofilesetup/qtmoduleinfo.cpp#n253