Re: Problem with pack

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Aug 25, 2006, 09:12 UTC
Message-ID: <Pine.LNX.4.63.0608251104410.28360@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <44EEB8AD.5080703@arces.unibo.it>

Hi,

On Fri, 25 Aug 2006, Sergio Callegari wrote:

> git verify-pack -v pack-ebcdfbbda07e5a3e4136aa1f499990b35685bab4.idx
> fatal: failed to read delta-pack base object 2849bd2bd8a76bbca37df2a4c8e8b990811d01a7

Eeeh! Not good.

> 1) I am working on both a pc and a notebook, syncing the two everytime I move
> from one to the other.

So, you still have one "good" version? Please make a backup immediately. (If only to reproduce the problem.)

> On the PC I have git 1.4.2, on the notebook git 1.4.0. I am using "unison" as
> a syncing tool.
> Might the data loss have something to do with...
> - the version of git I am using or the mixing of two versions?

We tried very hard to maintain backward compatibility. So, it should be fine.

> - the syncing? I have noticed that after a sync, git is not immediately in a
> happy state...

That is okay. The "index" (remember, git has a staging area called "index") stores ctimes and mtimes, and these are not synced.

> 2) git unpack-objects seems to be able to extract some objects from the pack,
> but at a certain point it dies.
> - does it die on the first error or does it try to extract everything that is
> possible to extract after the error?

Since unpack-objects does not use the index, it cannot extract anything after the first error. We _could_ enhance unpack-objects to be nice and optionally take a pack-index to try to reconstruct as many objects as possible.

BTW I'd recommend not syncing with unison, but with the git transports: If your PC and Laptop are connected, you could do something like

	git pull laptop:my_project/.git

(Of course, you have to adjust it for your setup.) This would sync your repository on the PC with the one on the laptop.

Hth, Dscho