> as: unrecognized option `-O2' Ok, I just worked out the problem - or at least I discovered a workaround. If I run: ./configure --prefix=/usr/local [...] then I get the error during compilation, but if instead I run ./configure --prefix=/usr [...] then it appears to work perfectly...! No idea what's going on, but at least it works and hopefully it won't overwrite my existing compiler when I install it ;-) Cheers, Adam.