deferred error : (error «Selecting deleted buffer»)

(defun my/kill-all-buffers-except-toolbox ()
  "Kill all buffers except current one and toolkit (*Messages*, *scratch*). Close other windows."
  ;; (interactive)
  (mapc 'kill-buffer (remove-if
                      (lambda (x)
                        (or
                         ;; (string-equal (buffer-name) (buffer-name x))
                         (string-equal "*Messages*" (buffer-name x))
                         (string-equal "*ycmd-server*" (buffer-name x))
                         (string-equal "*scratch*" (buffer-name x))))
                      (buffer-list)))
  (delete-other-windows))

;; load bookmarks & kill all buffer's
(global-set-key (kbd "C-x r b")
                (lambda ()
                  (interactive)
                  (bookmark-jump
                   (completing-read "Jump to bookmark: " (bookmark-all-names)))
                  ;; save current dir
                  (defvar my-cur-dir (file-name-directory (buffer-file-name)))
                  (switch-to-buffer "*scratch*")
                  (my/kill-all-buffers-except-toolbox)
                  ;; revert current dir
                  (setq default-directory my-cur-dir)))