# if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 1 || __GLIBC__ > 2) \
&& !defined(__ia64__)
# ifndef GC_HAVE_BUILTIN_BACKTRACE
-# define GC_HAVE_BUILTIN_BACKTRACE
+/* # define GC_HAVE_BUILTIN_BACKTRACE */
# endif
# endif
# if defined(__i386__) || defined(__x86_64__)