For Ubuntu:

sudo apt-get install libqt5multimedia5-plugins qtmultimedia5-dev qttools5-dev qttools5-dev-tools libqt5opengl5-dev qtbase5-dev libusb-1.0 librtlsdr-dev
mkdir out && cd out && cmake ../ && make

"librtlsdr-dev" is in the "universe" repo. (utopic 14.10 amd64.)

Use "cmake ../ -DKERNEL=ON" to build the Linux kernel driver (Experimental). Needs a recent kernel and libv4l2. Will need extra work to support Airspy and Hackrf. Needs "cp KERNEL_SOURCE/include/linux/compiler.h /usr/include/linux/" and "cp KERNEL_SOURCE/include/uapi/linux/videodev2.h /usr/include/uapi/linux/" and package "libv4l-dev".

The Gnuradio plugin source needs extra packages, including "liblog4cpp-dev libboost-system-dev gnuradio-dev libosmosdr-dev"