https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77512
--- Comment #11 from michael at mijobe dot org --- I used contrib/download_prerequisites to install the required versions of GMP, MPFR, MPC and ISL: gmp-4.3.2 isl-0.15 mpc-0.8.1 mpfr-2.4.2
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77512
--- Comment #11 from michael at mijobe dot org --- I used contrib/download_prerequisites to install the required versions of GMP, MPFR, MPC and ISL: gmp-4.3.2 isl-0.15 mpc-0.8.1 mpfr-2.4.2