On 2016-08-04 22:23, Stefan Monnier wrote:
>>         (setq num-nonmacro-input-events (1+ num-nonmacro-input-events))
> 
> This should be in the server.el's process sentinel, so as to consider
> emacsclient connections as "nonmacro input event".

Hmm. Even with that, I'm not sure. Take the following (untested) program:

(condition-case err1 
    (condition-case err2
        (error "A")
      (error (error "B)))
  (error (message "Oups")))

Suppose I want to capture one backtrace for each of the signals in this program.  Assuming I register a debugger that re-throws all errors that it receives, won't the second error slip through, due to the nonmacro input event counter not having been increased?

Clément.