Possible fix 12360. If it doesn't help, it doesn't hurt, AFAIK...

Jeroen van Wolffelaar · Jeroen van Wolffelaar · commit 6da0268c2ab2 · 2001-08-10T20:18:42.000Z
diff --git a/main/network.c b/main/network.c
@@ -33,6 +33,10 @@
 #include <sys/socket.h>
 #endif
 
+#ifndef _FCNTL_H
+#include <fcntl.h>
+#endif
+
 #ifndef PHP_WIN32
 #include <netinet/in.h>
 #include <netdb.h>
