popup error message with flymake at current line

support-haskell.el

(defun flymake-display-err-menu-for-current-line ()
  (interactive)
  (let* ((line (flymake-current-line-no))
         (line-err-info (flymake-find-err-info flymake-err-info line))
         (error-infos (nth 0 line-err-info))
         (eof-char (char-to-string 0)))
    (when error-infos
      (loop for error-info in error-infos
            for message = (flymake-ler-text error-info)
            for file    = (flymake-ler-file error-info)
            for line    = (flymake-ler-line error-info)
            for filemsg = (or (and file " - %s(%d)" file line) "")

            ;; @@ remove EOF char, haskell error message contain EOF
            for removed-eof = (replace-regexp-in-string eof-char "\n" message)
            collect (format "%s%s" removed-eof filemsg) into messages
            finally
            (popup-tip (mapconcat 'identity
                                  (delete-duplicates messages :test #'string=)
                                  "\n"))))))