From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andreas Bombe <andreas.bombe@mytum.de>
Subject: Re: current git kernel has strange problems during bisect
Date: Thu, 15 Jan 2009 17:54:25 +0100
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References: <200901111602.53082.borntraeger@de.ibm.com> <20090111194258.GA4840@uranus.ravnborg.org> <alpine.LFD.2.00.0901111200330.6528@localhost.localdomain> <200901112239.20306.borntraeger@de.ibm.com> <f73f7ab80901131226s6af7730cucf9c44bc2b4f9545@mail.gmail.com>
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Cc: Christian Borntraeger <borntraeger@de.ibm.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Sam Ravnborg <sam@ravnborg.org>,
	Johannes Schindelin <Johannes.Schindelin@gmx.de>,
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To: Kyle Moffett <kyle@moffetthome.net>
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On Tue, Jan 13, 2009 at 03:26:09PM -0500, Kyle Moffett wrote:
> On Sun, Jan 11, 2009 at 4:39 PM, Christian Borntraeger
> <borntraeger@de.ibm.com> wrote:
> > In my opinion we should really avoid subtree merges in the future as a curtesy
> > to people who do the uncool work of testing, problem tracking and bisecting.
> > </rant>
> 
> As an alternative, you can relatively easily rewrite the following
> independent histories:
> 
> A -- B -- C
> X -- Y -- Z
> 
> To look like this:
> 
> A -- B -- C -- X' -- Y' -- Z'
> 
> Where X' is (C + sub/dir/X), Y' is (C + sub/dir/Y), etc...

Given that the subtree may have been in development for a long time, it
is almost a certainty that the older commits may compile on A but not
on C.  By basing it all on C you create a lot of uncompilable commits
which hurt bisection just as bad.  At least with missing kernel sources
it is obvious that an attempt at compilation is futile and a waste of
time.