in the Files for Mac:
DEP OSX music/core-audio_midi.mm
DEP OSX sound/core-audio_sound.mm
There is the line
#import <cocoa/cocoa.h>
I think it must be
#import <Cocoa/Cocoa.h>
With a Big "C" ..... The Files in the SDK have a Big C ....
almost certainly worth changing this. the OS X file system is not case sensitive but should be simple enough to fix :-)