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From: Eli Zaretskii <eliz@gnu.org>
Newsgroups: gmane.emacs.devel
Subject: Re: Help please! To track down GC trying to free an already freed
	object.
Date: Tue, 02 Apr 2019 22:21:26 +0300
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Cc: acm@muc.de, emacs-devel@gnu.org
To: "Daniel Colascione" <dancol@dancol.org>
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> Date: Tue, 2 Apr 2019 12:09:59 -0700
> From: "Daniel Colascione" <dancol@dancol.org>
> Cc: emacs-devel@gnu.org
> 
> rr is incredibly helpful for debugging this sort of problem. See
> https://rr-project.org/. You can record an rr session containing the
> crash, replay it, get to the crash, and then reverse-next, reverse-finish,
> and reverse-continue your way through the GC, running it in reverse until
> you find whatever it is that made mark_object on the dead object happen.

GDB supports reverse execution as well, on some platforms.