From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael J Gruber Subject: Re: [PATCH] Document 'git bisect fix'. Date: Wed, 16 Mar 2011 12:47:07 +0100 Message-ID: <4D80A33B.8020006@drmicha.warpmail.net> References: <20110311165802.GA3508@intel.com> <4D7A64670200007800035F4C@vpn.id2.novell.com> <4D7DE39302000078000362E6@vpn.id2.novell.com> <20110314095534.GB18058@elte.hu> <20110314104131.GG6275@bubble.grove.modra.org> <20110314122342.GA26825@elte.hu> <20110314131623.119020@gmx.net> <20110314210001.GE4586@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Ralf Wildenhues , Ingo Molnar , git@vger.kernel.org, Jan Beulich , "H.J. Lu" , "H. Peter Anvin" , Andrew Morton , Linus Torvalds , Thomas Gleixner To: Christian Couder X-From: git-owner@vger.kernel.org Wed Mar 16 12:50:59 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1PzpFW-0007rU-TW for gcvg-git-2@lo.gmane.org; Wed, 16 Mar 2011 12:50:47 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752063Ab1CPLum (ORCPT ); Wed, 16 Mar 2011 07:50:42 -0400 Received: from out5.smtp.messagingengine.com ([66.111.4.29]:59840 "EHLO out5.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751437Ab1CPLul (ORCPT ); Wed, 16 Mar 2011 07:50:41 -0400 Received: from compute1.internal (compute1.nyi.mail.srv.osa [10.202.2.41]) by gateway1.messagingengine.com (Postfix) with ESMTP id 973ED20A64; Wed, 16 Mar 2011 07:50:40 -0400 (EDT) Received: from frontend2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Wed, 16 Mar 2011 07:50:40 -0400 DKIM-Signature: v=1; a=rsa-sha1; c=relaxed/relaxed; d=messagingengine.com; h=message-id:date:from:mime-version:to:cc:subject:references:in-reply-to:content-type:content-transfer-encoding; s=smtpout; bh=nuWJAyfRUwGVnHdTOfnPBmHGAec=; b=ipJ/qxb59FpRC/C69fB9gNIsv6oQIq/cg3pXzaigrutmDew3bl/R7w/S0cxfngNgQPHL42XOh6Ht1Pam7QpP/RswmIs3F9oCfV+TUNG8TmCx8y7+hXWsOjgyxtydgXaQIzOVOD+S6drEDb5qjkibnhUjIGWNw+58N6/aBZtsrHU= X-Sasl-enc: gB+dbTy2Zhg7H8zjMwl7ctjWOfY1E5UdUe8yVm4dPJqW 1300276240 Received: from localhost.localdomain (whitehead.math.tu-clausthal.de [139.174.44.62]) by mail.messagingengine.com (Postfix) with ESMTPSA id 25ADF440452; Wed, 16 Mar 2011 07:50:39 -0400 (EDT) User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.15) Gecko/20110305 Remi/fc14 Lightning/1.0b3pre Thunderbird/3.1.9 In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Christian Couder venit, vidit, dixit 16.03.2011 10:52: > Hi, > > On Mon, Mar 14, 2011 at 10:00 PM, Ralf Wildenhues > wrote: >> git bisect is sometimes less effective than it could be in projects >> with long-lived but simple bugs (e.g., little-tested configurations). >> Rather than skipping vast revision ranges, it might be easier to fix >> them up from known bugfix branches. > > It's already possible to deal with this problem by creating a new > branch where the bug is fixed, and then using "git replace", so that > the new branch is used instead of the old one. > Please search for "git replace" in this doc: > > http://www.kernel.org/pub/software/scm/git/docs/git-bisect-lk2009.html > >> 'git bisect fix' teaches bisect about when some known bug was >> introduced and when it was fixed, so that bisect can merge in >> the fix when needed into new test candidates. > > Perhaps some people would find it easier to use what you suggest but > using git replace may be nicer because you have to create the new > branch once, so you need to fix merge or rebase problems only once. > And the new branch may be useful not only for bisecting, for example > to recreate old versions. I'd say the replace method is perfect for transporting an existing fix "back in time" when the range of non-bisectable commits is limited. But since you have to replace the right (most recent) commit in that range it is less convenient when you have a fix due to a changed/exotic build environment or such which you do not want in your mainline. Also, you have to rebase the whole history back to the commit which introduced the problem - and that could be the root commit if the bisect problems arise from a changed toolchain, like here. Michael P.S.: Did you cull cc on purpose or did gmane mess up? Readding AM, LT, TG