Needs some tweaking to get it to work. Not the usual mkoctfile stuff which appears to be fixed. This time it’s the link to gcc/g++ (required to build packages) which is revealed in a mysterious config.log file that it dumps on the system.
I did
cd /usr/bin
sudo ln -s llvm-gcc-4.2 gcc-4.2
sudo ln -s llvm-g++-4.2 g++-4.2
to fix it. Have fun.