updated for version 7.4.056
Problem: Mac: Compilation problem with OS X 10.9 Mavericks.
Solution: Include AvailabilityMacros.h when available. (Kazunobu Kuriyama)
diff --git a/src/os_unix.c b/src/os_unix.c
index cc02653..80459c9 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -804,6 +804,12 @@
* completely full.
*/
+#if defined(HAVE_AVAILABILITYMACROS_H) \
+ && defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) \
+ && (__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ >= 1090)
+# include <AvailabilityMacros.h>
+#endif
+
#ifndef SIGSTKSZ
# define SIGSTKSZ 8000 /* just a guess of how much stack is needed... */
#endif