[AUCTeX] "No connection to bus" message in Cygwin Emacs

[Sebastien Vauban]

Hello,

After opening a .tex file in Emacs, I got this when trying to compile
the document to PDF :

--8<---------------cut here---------------start------------->8---
C-c C-c is undefined
ad-handle-definition: `TeX-recenter-output-buffer' got redefined
File mode specification error: (dbus-error "No connection to bus" :session)
--8<---------------cut here---------------end--------------->8---

To make things clear, the same operation worked on almost the same LaTeX
document 5 min earlier... Though, I don't understand what can explain
the behavior change in the same Emacs session...

Any tip on what I should do or report here?

I've seen posts (from 2011) stating that such message should not be
displayed anymore... See
http://comments.gmane.org/gmane.emacs.auctex.devel/2585.  That makes me
really wonder about what's the cause of the problem here...

PS- The `TeX-recenter-output-buffer' message must come from this
    customization:

--8<---------------cut here---------------start------------->8---
  ;; Get colored PDFLaTeX output.
  (define-derived-mode latex-output-mode fundamental-mode "LaTeX-Output"
    "Simple mode for colorizing LaTeX output."
    (set (make-local-variable 'font-lock-defaults)
         '((("^!.*" .
             compilation-error-face)    ; LaTeX error
            ("^-+$" .
             compilation-info-face)     ; Latexmk separator
            ("^Package .* Warning: .*" .
             compilation-warning-face)
            ("Reference .* undefined" .
             compilation-warning-face)
            ("^\\(?:Overfull\\|Underfull\\|Tight\\|Loose\\).*" .
             font-lock-string-face)
            ("^LaTeX Font Warning:" .
             font-lock-string-face)
            ;; ...
            ))))

  (defadvice TeX-recenter-output-buffer
    (after leuven-colorize-latex-output activate)
    (with-selected-window (get-buffer-window (TeX-active-buffer))
      (latex-output-mode)))
--8<---------------cut here---------------end--------------->8---

PPS- I'm trying to use Cygwin Emacs instead of a Windows binary for the
     last couple of days, with the goal of fully switching to the Cygwin
     version if such problems are resolved.

     I've never had the above problem with the Windows binary.

Best regards,
  Seb

-- 
Sebastien Vauban