Re: fetch and bundle don't work in (semi-)broken repo

From: Nicolas Pitre <nico@fluxnic.net>
Date: Oct 19, 2010, 20:48 UTC
Message-ID: <alpine.LFD.2.00.1010191635030.2764@xanadu.home>
In-Reply-To: <20101019201139.GB28166@pengutronix.de>

On Tue, 19 Oct 2010, Uwe Kleine-König wrote:

Show 19 quoted lines

> Hi Jonathan,
> 
> On Tue, Oct 19, 2010 at 01:39:25PM -0500, Jonathan Nieder wrote:
> > Uwe Kleine-König wrote:
> > 
> > > 	ukl@hostname:~/path1/linux-2.6$ git fetch ~/path2/linux-2.6 sectionmismatches
> > > 	remote: Counting objects: 118, done.
> > > 	remote: error: unable to find 40aaeb204dc04d3cf15c060133f65538b43b13b0
> > > 	remote: Compressing objects: 100% (83/83), done.
> > > 	remote: fatal: unable to read 40aaeb204dc04d3cf15c060133f65538b43b13b0
> > > 	error: git upload-pack: git-pack-objects died with error.
> > > 	fatal: git upload-pack: aborting due to possible repository corruption on the remote side.
> > 
> > Sounds like alternates or workdir allowed gc to be overzealous, indeed.
> > 
> > Could you:
> > 
> >  1. Make a copy of the corrupted repo, just in case.
> >  2. Explode all backs with "git unpack-objects"

That's usually unnecessary. If the pack itself is corrupted, trying to unpack it all won't help.

Show 7 quoted lines

> I did:
> 
> 	mv .git/objects/pack .git/objects/pack.bak
> 	rm .git/objects/info/alternates
> 	for p in .git/objects/pack.bak/*.pack ~/path1/linux-2.6/.git/objects/pack/*.pack; do
> 		git unpack-objects < $p
> 	done

Ouch! You will end up with a multi-gigabyte repository, which will be abominably slow.

> >  3. Identify the missing object, as explained in
> >     Documentation/howto/recover-corrupted-blob-object.txt?

That's useful when you have only one corrupted object and you want to recreate it from raw material. But ideally you should simply find a pack that contains the problematic object in another repository and copy it with its index file into the broken repository.

> and I'm running git-fsck --full now over night as it's bedtime here.

Given that you exploded your repo into loose objects, it'll take _time_.

Nicolas