# Bisecting through the middle of a big merge? 5 messages from 2012-01-28 to 2012-01-28. Participants: walt, Andreas Schwab. Thread: https://gitlist.dev/t/29459 ## walt, 2012-01-28 00:03 Subject: Bisecting through the middle of a big merge? Message-ID: URL: https://gitlist.dev/e/jfve09%24ih5%241%40dough.gmane.org ``` My problem is that I lack a good mental model of what git does when it commits a big merge, and so I get lost when I try to bisect back through a merge. (I'm a tester, not a developer.) This specific recent example is causing me problems: Merge: b3c9dd1 85a0f7b Author: Linus Torvalds Date: Sun Jan 15 12:48:41 2012 -0800 Merge branch 'for-3.3/drivers' of git://git.kernel.dk/linux-block There are many individual commits from Tejun Heo et al included in that one big commit from Linus. Unfortunately for me, some of those commits cause other problems that I'm not trying to bisect; other problems that evidently get fixed by other commits in the same big merge. So I do 'git bisect skip' six or eight times until the 'false' bug goes away, and that leaves me at the end of the bisect without finding the individual commit that's causing my 'real' bug. How do you experts handle this kind of problem? Thanks for any clues. ``` ## Andreas Schwab, 2012-01-28 08:55 Subject: Re: Bisecting through the middle of a big merge? Message-ID: URL: https://gitlist.dev/e/m239b0fbpb.fsf%40igel.home In-Reply-To: ``` walt writes: > There are many individual commits from Tejun Heo et al included > in that one big commit from Linus. Unfortunately for me, some of > those commits cause other problems that I'm not trying to bisect; > other problems that evidently get fixed by other commits in the > same big merge. > > So I do 'git bisect skip' six or eight times until the 'false' bug > goes away, and that leaves me at the end of the bisect without finding > the individual commit that's causing my 'real' bug. > > How do you experts handle this kind of problem? If you can identify the commit that fixes the unrelated problem you can try to cherry-pick it during the bisect. Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ``` ## walt, 2012-01-28 18:15 Subject: Re: Bisecting through the middle of a big merge? Message-ID: URL: https://gitlist.dev/e/jg1e0t%245cs%241%40dough.gmane.org In-Reply-To: ``` On 01/28/2012 12:55 AM, Andreas Schwab wrote: > walt writes: > >> There are many individual commits from Tejun Heo et al included >> in that one big commit from Linus. Unfortunately for me, some of >> those commits cause other problems that I'm not trying to bisect; >> other problems that evidently get fixed by other commits in the >> same big merge. >> >> So I do 'git bisect skip' six or eight times until the 'false' bug >> goes away, and that leaves me at the end of the bisect without finding >> the individual commit that's causing my 'real' bug. >> >> How do you experts handle this kind of problem? > > If you can identify the commit that fixes the unrelated problem you can > try to cherry-pick it during the bisect. Thanks Andreas. With an eye to doing that, is there an easy way to get a list of all the commits included in Linus's merge? (I mean a more accurate list than Linus casually mentions in his commit message.) Trying to build that mental model I mentioned: All the commits from Tejun Heo are dated mid-December but Linus didn't commit them until mid-January. When I'm bisecting through that merge, git builds the kernels with names like vmlinuz-3.2.0-rc5-foo, i.e. names a month older than Linus's current kernel version. Where does git get those older names during the bisect? And does my working tree exclude all of Linus's commits made later than 3.2.0-rc5-foo? Many thanks. ``` ## Andreas Schwab, 2012-01-28 19:47 Subject: Re: Bisecting through the middle of a big merge? Message-ID: URL: https://gitlist.dev/e/m2ty3ffw2f.fsf%40igel.home In-Reply-To: ``` walt writes: > With an eye to doing that, is there an easy way to get a list of all > the commits included in Linus's merge? $ git log merge-commit^..merge-commit Andreas. -- Andreas Schwab, schwab@linux-m68k.org GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." ``` ## walt, 2012-01-28 22:18 Subject: Re: Bisecting through the middle of a big merge? Message-ID: URL: https://gitlist.dev/e/jg1s7m%241qu%241%40dough.gmane.org In-Reply-To: ``` On 01/28/2012 11:47 AM, Andreas Schwab wrote: > walt writes: > >> With an eye to doing that, is there an easy way to get a list of all >> the commits included in Linus's merge? > > $ git log merge-commit^..merge-commit Amazing. And obvious now that you've already told me the answer. I'm not thinking like a developer yet, but I'm working on it :) ```