+(defun describe-variable-custom-version-info (variable)
+ (let ((custom-version (get variable 'custom-version))
+ (cpv (get variable 'custom-package-version))
+ (output nil))
+ (if custom-version
+ (setq output
+ (format "This variable was introduced, or its default value was changed, in\nversion %s of Emacs.\n"
+ custom-version))
+ (when cpv
+ (let* ((package (car-safe cpv))
+ (version (car (cdr-safe cpv)))
+ (pkg-versions (assq package customize-package-emacs-version-alist))
+ (emacsv (cdr (assoc version pkg-versions))))
+ (if (and package version)
+ (setq output
+ (format (concat "This variable was introduced, or its default value was changed, in\nversion %s of the %s package"
+ (if emacsv
+ (format " that is part of Emacs %s" emacsv))
+ ".\n")
+ version package))))))
+ output))
+