Re: Using 'git bisect' to pinpoint errors in .emacs. Was: Fatal error 11: Segmentation Fault

[Eli Zaretskii]

> From: Vegard Vesterheim <vegard.vesterheim@uninett.no>
> Date: Wed, 3 Apr 2019 10:51:38 +0000
> Cc: "help-gnu-emacs@gnu.org" <help-gnu-emacs@gnu.org>
> 
> After upgrading to emacs25 some time ago, I experienced that emacs would
> segfault every so often. I have been using emacs for many years, and my
> .emacs file is constantly tweaked, so it was difficult to pinpoint what
> was causing the crash. I finally discovered a way to reliably reproduce
> this segfault. Since I have my .emacs in git, it was simply a matter of
> supplying a small script that triggered the error to the 'git bisect
> run' command. After running for a while git was able to pinpoint the
> change in my .emacs that triggered the bug.

FWIW, IME bisection is only helpful when you cannot reproduce the
issue at will or easily enough.  If reproduction is easy, it is much
more useful to debug the failure than to find the change which is to
blame, because finding that change in most cases still doesn't tell
you how to fix the problem, certainly not with a segfault.