older versions seem to output a broken configure script.
@@ -1,5 +1,5 @@
dnl Process this file with autoconf to produce a configure script.
-AC_PREREQ([2.63])
+AC_PREREQ([2.65])
AC_INIT
AC_CONFIG_SRCDIR([src/SDL.c])
AC_CONFIG_HEADERS([include/SDL_config.h])