Started on GUSI2 and threading support.
diff --git a/Mac/mwerks/errno_unix.h b/Mac/mwerks/errno_unix.h
index 7f63ef6..2e6f171 100644
--- a/Mac/mwerks/errno_unix.h
+++ b/Mac/mwerks/errno_unix.h
@@ -29,6 +29,7 @@
 
 ******************************************************************/
 
+#ifndef USE_GUSI2
 #define ENOTDIR		(-120)
 #ifndef __MSL__
 #define EACCES		(-54)
@@ -40,6 +41,7 @@
 #define ENFILE		(-42)
 #define	EIO			(-36)
 #define ENOSPC		(-34)
+#endif
 
 #define ESRCH		3
 #define EINTR		4