1.593: fix the non-upgrade by not trying to find-package into a non-existing package. Sigh.

asdf.lisp

@@ -49,10 +49,12 @@
 (cl:in-package :cl-user)
 
 (eval-when (:compile-toplevel :load-toplevel :execute)
-  (let ((sym (find-symbol "*ASDF-REVISION*" :asdf)))
+  (let ((asdf (find-package :asdf)))
+    (when asdf
+      (let ((sym (find-symbol "*ASDF-REVISION*" asdf)))
         (when sym
           (unexport sym)
-      (unintern sym))))
+          (unintern sym))))))
 
 (defpackage #:asdf
   (:documentation "Another System Definition Facility")
@@ -173,7 +175,7 @@
 ;;;;
 (defparameter *asdf-version*
   ;; the 1+ hair is to ensure that we don't do an inadvertent find and replace
-  (subseq "VERSION:1.592" (1+ (length "VERSION"))))
+  (subseq "VERSION:1.593" (1+ (length "VERSION"))))
 
 (defun asdf-version ()
   *asdf-version*)