Index: /trunk/source/lib/compile-ccl.lisp
===================================================================
--- /trunk/source/lib/compile-ccl.lisp	(revision 13416)
+++ /trunk/source/lib/compile-ccl.lisp	(revision 13417)
@@ -520,8 +520,12 @@
 (defvar *ccl-save-source-locations* :no-text)
 
-(defun rebuild-ccl (&key update full clean kernel force (reload t) exit reload-arguments verbose optional-features (save-source-locations *ccl-save-source-locations*))
+(defun rebuild-ccl (&key update full clean kernel force (reload t) exit
+		    reload-arguments verbose optional-features
+		    (save-source-locations *ccl-save-source-locations*)
+		    allow-constant-redefinition)
   (let* ((*build-time-optional-features* (intersection *known-optional-features* optional-features))
          (*features* (append *build-time-optional-features* *features*))
-	 (*save-source-locations* save-source-locations))
+	 (*save-source-locations* save-source-locations)
+	 (*cerror-on-constant-redefinition* (not allow-constant-redefinition)))
     (when *build-time-optional-features*
       (setq full t))