GNU bug report logs - #65837
30.0.50; Debugger in non-main threads

Previous Next

Full log

Message #8 received at 65837 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Helmut Eller <eller.helmut <at> gmail.com>
Cc: 65837 <at> debbugs.gnu.org
Subject: Re: bug#65837: 30.0.50; Debugger in non-main threads
Date: Sat, 09 Sep 2023 14:14:20 +0300

> From: Helmut Eller <eller.helmut <at> gmail.com>
> Date: Sat, 09 Sep 2023 11:15:52 +0200
> 
> When the debugger is entered in a non-main thread, like so
> 
>   emacs -Q --eval '(make-thread (lambda() (debug)))'
> 
> Then debugger-quit doesn't work as usual, instead it prints
> 
>   debugger-quit: No catch for tag: top-level, nil
> 
> or it prints
> 
>   Back to top level
> 
> but doesn't actually close the debugger window.
> 
> Also, debugger-continue doesn't work as usual, instead it sometimes prints:
> 
>   debugger-continue: No catch for tag: exit, nil
> 
> sometimes it prints:
> 
>   Continuing.
> 
> without deleting the debugger window, sometimes it manages to leave the
> debugger.
> 
> If Emacs is started with "emacs -Q -nw" then the behaviour seems to be a
> bit more uniform, but equally useless.

Yes, error handling in non-main threads is generally rudimentary and
barely useful.  For example, if a thread signals an error, it simply
silently exits and leaves the error form in a variable that can be
accessed via thread-last-error.  AFAIR, it is not trivial to improve
the thread error handling significantly, but patches are welcome, of
course.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.