anchor.diff:        (ospm:list-generations (profile source)))))
     (:accessor-name-transformer (class*:make-name-transformer name)))
   
  -(defun make-os-package-buffer ()
  -  (make-buffer :no-history-p t
  -               :load-url-p nil
  -               :title "*OS packages*"))
  +(defun ensure-os-package-buffer ()
  +  (or (find-buffer 'os-package-manager-mode)
  +      (sera:lret ((new-buffer (make-buffer :no-history-p t ; TODO: Don't use `make-buffer'.
  +                                           :load-url-p nil
  +                                           :status :finished ; TODO: Restore `internal-buffer'?
  +                                           :title "*OS packages*")))
  +        (enable (make-instance 'nyxt/os-package-manager-mode:os-package-manager-mode
  +                               :buffer new-buffer)))))
   
   (defun %describe-os-package (packages)
  -  (let* ((buffer (or (find-buffer 'os-package-manager-mode)
  -                     (enable (make-instance 'nyxt/os-package-manager-mode:os-package-manager-mode
  -                                            :buffer (make-os-package-buffer))))))
  +  (let* ((buffer (ensure-os-package-buffer)))
       (flet ((format-inputs (inputs)
                (spinneret:with-html
                  (dolist (input inputs)
  
positive.code:                        :sources (list (make-instance 'os-generation-source
                                                       :profile profile))
                         :prompt "Generation")))
           (buffer (or (find-buffer 'os-package-manager-mode)
                       (enable-modes '(nyxt/os-package-manager-mode:os-package-manager-mode)
                                     (make-os-package-buffer)))))
      (echo "Loading package database...")
      (nyxt::html-set
       (spinneret:with-html-string
  
negative.code:                                   (prompt
                                     :sources '(os-package-source)
                                     :prompt "List files of OS package(s)")))
           (buffer (ensure-os-package-buffer)))
      (echo "Computing file list...")
      (nyxt::html-set
       (spinneret:with-html-string
  