flymake python pep8 error messages disappeared

Question

I setup flymake with pep8 to validate style of python files with the following configuration:

(when (load "flymake" t)
 (defun flymake-pylint-init ()
   (let* ((temp-file (flymake-init-create-temp-buffer-copy
                      'flymake-create-temp-inplace))
          (local-file (file-relative-name
                       temp-file
                       (file-name-directory buffer-file-name))))
         (list "pep8" (list "--repeat" local-file))))

 (add-to-list 'flymake-allowed-file-name-masks
              '("\\.py\\'" flymake-pylint-init)))

(defun my-flymake-show-help ()
  (when (get-char-property (point) 'flymake-overlay)
    (let ((help (get-char-property (point) 'help-echo)))
      (if help (message "%s" help)))))

(add-hook 'python-mode-hook
      '(lambda() (flymake-mode)))

It worked fine from the start. I just evaluated it in a scratch buffer and worked for several weeks, then I suddenly closed Emacs and after that restart messages are not shown when you navigate to a problem line, but these lines are still highlighted.

(message "DDD") - works

pep8 works fine too in a terminal

Any ideas? I think I forgot some step.

Answer 1

At last I found that missing line.

(add-hook 'post-command-hook 'my-flymake-show-help)