Subject: 23.0.60; debug-on-error sometimes fails to debug on error

From: Markus Triska <[email-masked]>
Date: Tue, 9 Sep 2008 01:29:54 +0200 (CEST)

In emacs -Q, when I evaluate the forms:

   (defun my-err ()
     (error "Err"))

   (toggle-debug-on-error)   

   (add-hook 'post-command-hook 'my-err)

I get:

   Error in post-command-hook: (error Err)

and do not see the debugger.

In GNU Emacs 23.0.60.11 (i386-apple-darwin8.11.1, GTK+ Version 2.12.9)
 of 2008-09-02 on mt-computer.local
Windowing system distributor `The XFree86 Project, Inc', version 11.0.40400000
Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: nil
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en.UTF-8
  value of $XMODIFIERS: nil
  locale-coding-system: nil
  default-enable-multibyte-characters: t