QMake version 3.0
Using Qt version 5.3.2 in /usr/lib/x86_64-linux-gnu
should be sufficient to compile LibreCAD.
I will check things later on my Ubuntu machine, where it builds fine.
Latest sources also build fine on launchpad.net for librecad-daily ppa.
But I reckon, that it is something with the environment/configuration on your Debian box.