I have grepped for auto_link/(GMP|MFR)|AUTO_?LINK_(GMP|MPFR) and I removed completely any support for auto-linking of GMP and MPFR from CGAL. That is no longer necessary, nor relevant, no that we provide precompiled GMP and MPFR libraries under standard names libgmp-10.lib and libmpfr-4.lib. To test in candidates: Core Installation Number_types