http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59878
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- "Use --with-isl=system to direct CLooG to pick up an already installed ISL, otherwise it will use ISL 0.11.1 as bundled with CLooG" doesn't exactly suggest that using the ISL 0.11.1 bundled with CLooG will not work though (it's exactly the version suggested ...) So the wording could be improved.