FYI,
Just installed on a new machine fedora 18 and run the build-gnuradio.
Just add F18 support to it. Replace (or add |18) the switch on ~line
324 and it will do the job
From 12|13|14|15|16|17)
to 12|13|14|15|16|17|18)
osmocom.org server seems to off-line so in my case it couldn’t be built.
Patrik