emacs23 pops up debugger way too frequently

Since I've upgraded to Ubuntu lucid and emacs23, Emacs p开发者_开发问答ops up the debugger in situations, where emacs22 does not.

For example, when hitting C-c C-c in org-mode, emacs22 simply states can do nothing useful at this location, whereas in emacs23 the debugger shows up.

 Debugger entered--Lisp error: (error "C-c C-c can do nothing useful at this location")
   signal(error ("C-c C-c can do nothing useful at this location"))
   error("C-c C-c can do nothing useful at this location")
   org-ctrl-c-ctrl-c(nil)
   call-interactively(org-ctrl-c-ctrl-c nil nil)

That only illustrates the pattern -- the behavior is not limited to org-mode. Occurring every 3 minutes, it really annoys me. How can I prevent it?

I've already tried to stop this using debug-on-error and stack-trace-on-error: it didn't work.

Chances are that something is setting debug-on-error after you've configured it.

Some ways to confirm:

Start Org Mode, press C-c C-c to enter the debugger, and q to exit again. Now M-x set-variable RET debug-on-error RET nil RET, and try it again.

Next, try starting emacs with the -q argument (to avoid executing your init file), and then entering org mode and hitting C-c C-c. This should not trigger the debugger.

You could use M-x rgrep RET debug-on-error RET (or maybe debug-on-error t) on your site-lisp and custom lisp directories, to help track down which library is responsible.

As I could replicate your issue, I've just done this for myself. For me, the culprit was: (load "nxhtml/autostart.el"). I'm upgrading nxhtml now, which I suspect will resolve things in my case.

Edit: or not.

The current version of nxhtml has moved the statement from autoload.el into nxhtml-base.el. If this is the same culprit for you, you could either edit that file, or make sure that your customisation of the variable happens after nxhtml's autostart file executes.