Function needs extern keyword. 
In house patch. 

--- a/arc4random.c    2016-03-01 09:29:36.602447178 -0800
+++ b/arc4random.c    2016-03-01 10:17:51.627857034 -0800
@@ -445,8 +445,8 @@ arc4random_stir(void)
 #endif

 #ifndef ARC4RANDOM_NOADDRANDOM
-ARC4RANDOM_EXPORT void
-arc4random_addrandom(const unsigned char *dat, int datlen)
+extern void
+arc4random_addrandom(uchar_t *dat, size_t datlen)
 {
        int j;
        _ARC4_LOCK();
@@ -477,7 +477,7 @@ arc4random(void)
 }
 #endif

-ARC4RANDOM_EXPORT void
+extern void
 arc4random_buf(void *_buf, size_t n)
 {
        unsigned char *buf = _buf;