At a directory without stack configuration, emacs is devastated by the initialization step of Intero. This is a record of my atemps to fix.
(defun auto-revert-notify-add-watch ()
"Enable file notification for current buffer's associated file."
;; We can assume that `buffer-file-name' and
;; `auto-revert-use-notify' are non-nil.
(if (or (string-match auto-revert-notify-exclude-dir-regexp
(expand-file-name (or default-directory "")))
(file-symlink-p (or buffer-file-name default-directory)))
;; Fallback to file checks.
(setq-local auto-revert-use-notify nil)
(when (not auto-revert-notify-watch-descriptor)
(setq auto-revert-notify-watch-descriptor
(ignore-errors
(if buffer-file-name
(file-notify-add-watch
(expand-file-name buffer-file-name default-directory)
'(change attribute-change)
'auto-revert-notify-handler)
(file-notify-add-watch
(expand-file-name default-directory)
'(change)
'auto-revert-notify-handler))))
(if auto-revert-notify-watch-descriptor
(progn
(puthash
auto-revert-notify-watch-descriptor
(cons (current-buffer)
(gethash auto-revert-notify-watch-descriptor
auto-revert-notify-watch-descriptor-hash-list))
auto-revert-notify-watch-descriptor-hash-list)
(add-hook 'kill-buffer-hook
#'auto-revert-notify-rm-watch nil t))
;; Fallback to file checks.
(setq-local auto-revert-use-notify nil)))))