Index: /trunk/ccl/lisp-kernel/thread_manager.c
===================================================================
--- /trunk/ccl/lisp-kernel/thread_manager.c	(revision 4980)
+++ /trunk/ccl/lisp-kernel/thread_manager.c	(revision 4981)
@@ -490,4 +490,8 @@
 #ifdef LINUX
   arch_prctl(ARCH_SET_GS, (natural)tcr);
+#endif
+#ifdef DARWIN
+  /* There's no way to do this yet.  See DARWIN_GS_HACK */
+  /* darwin_set_x8664_fs_reg(tcr); */
 #endif
   tcr->linear = tcr;