Workaround for this error: ad-Advice-package--add-to-archive-contents: Symbol's function definition is void: package-desc-vers

gistfile1.el

;; diff --git a/melpa-autoloads.el b/melpa-autoloads.el

(defadvice package--add-to-archive-contents (around package-filter-add-to-archive-contents (package archive) activate compile) "\
 Add filtering of available packages using `package-filter-function',
-if non-nil." (when (and package-filter-function (funcall package-filter-function (car package) (package-desc-vers (cdr package)) archive)) ad-do-it))
+if non-nil." (when (and package-filter-function (funcall package-filter-function (car package) (package--ac-desc-version (cdr package)) archive)) ad-do-it))

;; diff --git a/melpa.el b/melpa.el

@@ -84,7 +84,7 @@ if non-nil."
   (when (and package-filter-function
              (funcall package-filter-function
                       (car package)
-                      (package-desc-vers (cdr package))
+                      (package--ac-desc-version (cdr package))
                       archive))
     ad-do-it))