CGAL_VALGRIND_ENABLE

--- CGAL-3.4/include/CGAL/Interval_nt.h
+++ CGAL-3.4/include/CGAL/Interval_nt.h
@@ -149,11 +149,13 @@
       // The macros CGAL_IA_MUL and CGAL_IA_DIV stop constant propagation only
       // on the second argument, so if -fno-rounding-math, the compiler optimizes
       // the 2 negations and we get wrong rounding.
+#if 0
       typename Interval_nt<>::Internal_protector P;
       CGAL_assertion_msg(-CGAL_IA_MUL(-1.1, 10.1) != CGAL_IA_MUL(1.1, 10.1),
                          "Wrong rounding: did you forget the -frounding-math option if you use GCC?");
       CGAL_assertion_msg(-CGAL_IA_DIV(-1, 10) != CGAL_IA_DIV(1, 10),
                          "Wrong rounding: did you forget the -frounding-math option if you use GCC?");
+#endif
   }
};