I'm trying to configure GCC 4.7.2, but it's failing with configure: error: Unable to find a usable PPL I've looked in GCC prerequisites page and PPL isn't mentioned anywhere. I'm using CLooG 0.17.0, which uses ISL, and as such no longer requires PPL (as far as I can tell) Is there some other requirement on PPL in GCC which means I still need PPL, or am I missing some flag from my configure line? I am passing the following options to configure: --enable-cloog-backend=isl --with-cloog=$PREFIX --with-isl=$PREFIX --with-gmp=$PREFIX --with-mpfr=$PREFIX --with-mpc=$PREFIX Thanks Steve