missing header

Index: src/SDL/OOSDLSoundMixer.m
--- src/SDL/OOSDLSoundMixer.m.orig
+++ src/SDL/OOSDLSoundMixer.m
@@ -49,6 +49,9 @@ SOFTWARE.
 #import "OOCocoa.h"
 #import "OOSDLSoundInternal.h"
 
+#include <assert.h>
+
+
 
 static OOSoundMixer *sSingleton = nil;