If you are interested by installing gnu-radio from pybombs only, then read requirements for build it from sources, or look at build-script where you can see all needed dependencies for successfull build. Or, just run it, and it will do all job itself.
UPD: to avoid some possible errors, check if you gcc-compiler version are >= 5, but not => 6
UPD2: After reading the comment below, I will post a list of dependencies from the above script and, since you did not provide information about your version of the Ubuntu, I will use pkg-list for 15/16.
libqwt6 libfontconfig1-dev libxrender-dev libpulse-dev swig g++
automake autoconf libtool python-dev libfftw3-dev
libcppunit-dev libboost-all-dev libusb-dev libusb-1.0-0-dev fort77
libsdl1.2-dev python-wxgtk2.8 git-core
libqt4-dev python-numpy ccache python-opengl libgsl0-dev
python-cheetah python-mako python-lxml doxygen qt4-default qt4-dev-tools libusb-1.0-0-dev
libqwt5-qt4-dev libqwtplot3d-qt4-dev pyqt4-dev-tools python-qwt5-qt4
cmake git-core wget libxi-dev python-docutils gtk2-engines-pixbuf r-base-dev python-tk
liborc-0.4-0 liborc-0.4-dev libasound2-dev python-gtk2 libzmq libzmq-dev libzmq1 libzmq1-dev python-requests
python-sphinx comedi-dev python-zmq libncurses5 libncurses5-dev python-wxgtk3.0
Also, if you have already installed gnuradio via apt-get i'll recommend to remove it to avoid possible errors. If something goes wrong, you can always install them back :)
pkg-config
installed? It is a dependency that produces the above error.sud apt-get install pkg-config
it should either install it or tell you that it's already installed.