From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Justin P. Mattock" Subject: Re: help reverting a merge Date: Mon, 30 Nov 2009 00:31:26 -0800 Message-ID: <4B1382DE.1030506@gmail.com> References: <20091130081315.GA587@coredump.intra.peff.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Christian Couder , git@vger.kernel.org To: Jeff King X-From: git-owner@vger.kernel.org Mon Nov 30 09:31:31 2009 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.176.167]) by lo.gmane.org with esmtp (Exim 4.50) id 1NF1fO-0002f3-VV for gcvg-git-2@lo.gmane.org; Mon, 30 Nov 2009 09:31:31 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752067AbZK3IbU (ORCPT ); Mon, 30 Nov 2009 03:31:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751944AbZK3IbT (ORCPT ); Mon, 30 Nov 2009 03:31:19 -0500 Received: from mail-gx0-f212.google.com ([209.85.217.212]:64093 "EHLO mail-gx0-f212.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750869AbZK3IbS (ORCPT ); Mon, 30 Nov 2009 03:31:18 -0500 Received: by gxk4 with SMTP id 4so1624699gxk.8 for ; Mon, 30 Nov 2009 00:31:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from :user-agent:mime-version:to:cc:subject:references:in-reply-to :content-type:content-transfer-encoding; bh=7of+ucU1for0Gdj88FWNB5Pva1MNVM8F3IPphjKqLiA=; b=oUw5PDZX1m6/HjlbNMjrNaFCYZ5th17xGqGAZENh5l0Ti0yV0Xc4YXTUfdO4FtFqKz V9fxpdmeJRZKEFvbr2f5ljl27RY5pjvqKmeQe18rHhG90p0LCHRBNxVeyaJA4vL81oX7 SBYirlz7MzKIgPbl+0ILj7oJOj1BTs+qXHNoI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; b=PbYRnxtD4Oj4WTTa74DI0wg9vC0nx19mx9cotz54/ARPi/tM5/crh0OMx6xFkRmLqx /mGd+C69W6HWjRCrGhlo7PCKrs6sL6SkkdGLP1ARrwNnHuH7m16f845EMPahRsRS02c3 XLRNfBXF0rK+qsrG4qWCxIJv9dfAxucE/Am2k= Received: by 10.150.45.36 with SMTP id s36mr6601706ybs.334.1259569884897; Mon, 30 Nov 2009 00:31:24 -0800 (PST) Received: from ?10.0.0.95? (cpe-76-173-26-187.socal.res.rr.com [76.173.26.187]) by mx.google.com with ESMTPS id 9sm1539837ywf.50.2009.11.30.00.31.23 (version=SSLv3 cipher=RC4-MD5); Mon, 30 Nov 2009 00:31:24 -0800 (PST) User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091114 Lightning/1.0pre Thunderbird/3.0b4 In-Reply-To: <20091130081315.GA587@coredump.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: On 11/30/09 00:13, Jeff King wrote: > On Sun, Nov 29, 2009 at 03:24:09PM -0800, Justin Mattock wrote: > >> I've done a bisect on a problem with the kernel, >> and am a bit confused on what to do. i.g. the >> results are showing this: >> a03fdb7612874834d6847107198712d18b5242c7 is the first bad commit >> >> [...] >> >> how do I find out the commits in this merge to automatically >> revert to find the problem that's causing this bug? > > There is some discussion here: > > http://www.kernel.org/pub/software/scm/git/docs/user-manual.html#bisect-merges > > Basically neither merged branch was buggy on its own, but together they > have a bug. You can try rebasing the two sides of the merge into a > linear history, and then bisecting on that: > > # order doesn't matter here, but rebasing 12e0933 on top makes more > # sense since it has many fewer commits between it and the merge-base > # (and you'll need to fix up conflicts manually, so the smaller the > # rebase the better) > git checkout 12e0933 > git rebase 202c467 > > # to be safe, confirm that the rebase result shows your bug; > # we know that 202c467 doesn't have the bug, or we would not have > # bisected to the merge commit before > test test test > git bisect start > git bisect bad HEAD > git bisect good 202c467 > > which should give you the specific commit on the side branch where the > breakage occurred. > > This has been discussed as a technique before, and I have a feeling in > the back of my mind that maybe there was talk of having git-bisect help > with this case, but I don't think anything ever came of it. Christian > (cc'd) would probably know more. > > -Peff > ahh cool.. I'll have a read on this in the morning(late now)and see if I can do this to find the bug.(keep in mind might take some time i.g. not good at using git, but am willing to learn a thing or two). Justin P. Mattock