From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Using 'git bisect' to pinpoint errors in .emacs. Was: Fatal error 11: Segmentation Fault Date: Wed, 03 Apr 2019 14:14:39 +0300 Message-ID: <83bm1ne3xc.fsf@gnu.org> References: <86imvx5gyz.fsf@zoho.eu> <86ef6l5dwk.fsf@zoho.eu> <86a7h85ru5.fsf@zoho.eu> <865zrw55gm.fsf@zoho.eu> <5e7fb661-c090-4893-bcab-24ee4d96bea3@default> <86ftqzhd04.fsf@zoho.eu> <20190403081845.GA6609@tuxteam.de> <1spnq3gy4i.fsf_-_@uninett.no> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="3709"; mail-complaints-to="usenet@blaine.gmane.org" To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Wed Apr 03 13:14:41 2019 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hBdqq-0000oh-RL for geh-help-gnu-emacs@m.gmane.org; Wed, 03 Apr 2019 13:14:40 +0200 Original-Received: from localhost ([127.0.0.1]:40131 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBdqp-0006Dc-Q0 for geh-help-gnu-emacs@m.gmane.org; Wed, 03 Apr 2019 07:14:39 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:49851) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBdqa-0006DI-Jl for help-gnu-emacs@gnu.org; Wed, 03 Apr 2019 07:14:26 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:51821) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBdqa-0006l0-Es for help-gnu-emacs@gnu.org; Wed, 03 Apr 2019 07:14:24 -0400 Original-Received: from [176.228.60.248] (port=1738 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hBdqZ-0002G4-QZ for help-gnu-emacs@gnu.org; Wed, 03 Apr 2019 07:14:24 -0400 In-reply-to: <1spnq3gy4i.fsf_-_@uninett.no> (message from Vegard Vesterheim on Wed, 3 Apr 2019 10:51:38 +0000) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.org gmane.emacs.help:119864 Archived-At: > From: Vegard Vesterheim > Date: Wed, 3 Apr 2019 10:51:38 +0000 > Cc: "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.