anchor.diff:  (defun key-press (self x y gesture-spec)
     (declare (ignore self x y))
     (with-error-handler ()
  -    (alexandria:when-let ((key (gesture-spec-to-key gesture-spec)))
  +    (when-let (key (gesture-spec-to-key gesture-spec))
         (lem:send-event key))))
   
   (defun lem-pane-width (lem-pane)
  
positive.code:                      0 0))))
  
  (defun lem-pane-char-size (lem-pane)
    (maybe-update-cache-font lem-pane)
    (destructuring-bind (left top right bottom)
        (lem-pane-string-extent lem-pane)
      (values (- right left)
  
negative.code:      (gp:clear-graphics-port (lem-pane-pixmap lem-pane)))))
  
  (defun change-foreground (lem-pane color)
    (when-let (color (convert-color color nil))
      (setf (capi:simple-pane-foreground lem-pane) color)))
  
  (defun change-background (lem-pane color)
    (when-let (color (convert-color color nil))
      (setf (capi:simple-pane-background lem-pane) color)))
  