http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48378
--- Comment #13 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-04-02 23:32:10 UTC --- The docs for --with-gmp also point out you might need to use LD_LIBRARY_PATH so the gmp/mpfr/mpc libs will be found, which is the cause of the "cannot compute suffix" error, but I assume you didn't read those docs since you're not using --with-gmp I have no idea how you'll get the installed gcc to find those shared libs if you haven't bothered to install them and are giving the path to the build dir as with_gmp_lib, you're pretty much on your own if you don't want to follow the installation instructions. That's why you're finding it convoluted. I suggest just using my config-gcc.mk instead