#include <mach-o/reloc.h>
#include <sys/file.h>
#include <sys/stat.h>
-#include <libc.h>
+#include <unistd.h>
+/* Instead of unistd.h, this used to include libc.h.
+ "Nelson H. F. Beebe" <beebe@math.utah.edu> says that doesn't work
+ in system version 3.3. */
int malloc_cookie;