There are too many new features and bugfixes since the last release of
GNU Radio version 2.8. Please consult http://gnuradio.org/trac for details.
The following modules were added to this meta-pkgs/gnuradio:
* gnuradio-audio-jack
* gnuradio-audio-portaudio
* gnuradio-core-docs
* gnuradio-radio-astronomy
* gnuradio-trellis
* gnuradio-video-sdl
* usrp-docs
since they always need a C compiler, even when the source code is
completely in C++.
For some other packages, stated in the comment that a C compiler is
really not needed.