SYSTEM SPEC:
Kevin Ushley is absolutely right - the easiest way to make sure that the right compiler is being used is through Makevars
file. In my case, I added:
CXX = g++-4.8.1
PKG_CXXFLAGS = -std=c++11
This is what I have been missing - and it all worked afterwards. This works if you are compiling your package.