--- Python-2.7.13/Modules/_multiprocessing/multiprocessing.h.orig Fri Apr 28 18:23:17 2017 +++ Python-2.7.13/Modules/_multiprocessing/multiprocessing.h Fri Apr 28 18:23:52 2017 @@ -6,8 +6,10 @@ #ifdef __sun /* The control message API is only available on Solaris if XPG 4.2 or later is requested. */ +#ifndef _XOPEN_SOURCE #define _XOPEN_SOURCE 500 #endif +#endif #include "Python.h" #include "structmember.h"