Re: Debugging corrupt object generation

From: Nicolas Pitre <nico@cam.org>
Date: Nov 1, 2007, 23:57 UTC
Message-ID: <alpine.LFD.0.9999.0711011947220.21255@xanadu.home>
In-Reply-To: <Pine.LNX.4.64.0711012256080.17812@beast.quantumfyre.co.uk>

On Thu, 1 Nov 2007, Julian Phillips wrote:

Show 12 quoted lines

> I have been trying to import a repository using fast-import, and as part of
> this I have extended fast-import to support copying a path from any arbitrary
> commit.  This works fine on my small test repository.
> 
> However, when I run against my (vastly more complicated) real work repository
> things don't go so well.  I get a few thousand commits in, and then it breaks.
> It appears that I have somehow managed to create a corrupt object or
> something.
> 
> After a certain commit, and attempt to use that commit generates a "fatal:
> unable to apply delta".  This appears to be coming from unpack_delta_entry
> in sha1_file.c.

I suppose you mean "fatal: failed to apply delta", because "unable to apply delta" doesn't appear anywhere in the current source tree.

> Can anyone give me any hints as to how I find out what is causing the
> problem?  I'm not even sure what it is that isn't working ... and all
> attempts to replicate the problem with my test repository have failed.

Well, something is screwed for sure. Some object you're requesting is made of a delta, and that delta is bad, therefore patch_delta() returns NULL (you could instrument it to determine exactly why).

Maybe fast-import hasn't flushed the needed data to the pack yet?

Nicolas