threads / bug / 54555

BUG: commit-graph.c:1068 when doing `git pull`

Subject: BUG: commit-graph.c:1068 when doing `git pull`

## tl;dr

4 messages between Nov 2, 2020 and Nov 12, 2020.

replies: 3people: 3as markdown or json

herr.kaste· Nov 2, 2020, 18:30 UTC · lore

Hi all!

I'm stuck with this error message

    $ git pull
    BUG: commit-graph.c:1068: missing parent
104f5eb377763b2ed9663e8949aed265b69f000f for commit
c59ed9b7b6d4268ae6cb1069a9b51e02ad9aa1d8

This happens since the last `fetch --prune origin`.

If I do it again, I get

    $ git pull
    fatal: Unable to create 'C:/Users/c-flo/AppData/Roaming/Sublime
Text 3/Packages/GitSavvy/.git/objects/info/commit-graphs/commit-graph-chain.lock':
File exists.
    ...

And upon removing that file, I get the first error message again.

I actually don't know yet how to move on from here. I'm stuck, so I appreciate any help.

    $ git --version
    git version 2.29.2.windows.1

Regards Caspar Duregger

herr.kaste· Nov 2, 2020, 19:12 UTC · re: herr.kaste · lore

Re: BUG: commit-graph.c:1068 when doing `git pull`

    $ git commit-graph write

did the trick.

Let me know if you think there could be something useful to reproduce, somewhere.

Regards Caspar Duregger

Am Mo., 2. Nov. 2020 um 19:30 Uhr schrieb herr.kaste <herr.kaste@gmail.com>:

Show 31 quoted lines

>
> Hi all!
>
> I'm stuck with this error message
>
>     $ git pull
>     BUG: commit-graph.c:1068: missing parent
> 104f5eb377763b2ed9663e8949aed265b69f000f for commit
> c59ed9b7b6d4268ae6cb1069a9b51e02ad9aa1d8
>
> This happens since the last `fetch --prune origin`.
>
> If I do it again, I get
>
>     $ git pull
>     fatal: Unable to create 'C:/Users/c-flo/AppData/Roaming/Sublime
> Text 3/Packages/GitSavvy/.git/objects/info/commit-graphs/commit-graph-chain.lock':
> File exists.
>     ...
>
> And upon removing that file, I get the first error message again.
>
> I actually don't know yet how to move on from here.  I'm stuck, so I
> appreciate any help.
>
>     $ git --version
>     git version 2.29.2.windows.1
>
>
> Regards
> Caspar Duregger

Taylor Blau· Nov 12, 2020, 14:42 UTC · re: herr.kaste · lore

Re: BUG: commit-graph.c:1068 when doing `git pull`

Hi Caspar,

On Mon, Nov 02, 2020 at 08:12:07PM +0100, herr.kaste wrote:

Show 8 quoted lines

> A
>
>     $ git commit-graph write
>
> did the trick.
>
> Let me know if you think there could be something useful to reproduce,
> somewhere.

I think this is worth trying to reproduce. The first message you're seeing about the commit-graph-chain.lock already existing is a red-herring: it's likely that the last time you tried to generate a commit-graph, that it hit that same BUG() and left the stale lock laying around. (I can't remember off the top of my head whether we still run the atexit handlers upon a BUG(), but even still, I could believe that some other stray process left it laying around, too).

So, what's interesting is why your commit graph ended up in a state that it got some commit without all of its parents. If you could reproduce that state, that would be interesting.

Are you using shallow or partial clones?

Show 35 quoted lines

> Regards
> Caspar Duregger
>
> Am Mo., 2. Nov. 2020 um 19:30 Uhr schrieb herr.kaste <herr.kaste@gmail.com>:
> >
> > Hi all!
> >
> > I'm stuck with this error message
> >
> >     $ git pull
> >     BUG: commit-graph.c:1068: missing parent
> > 104f5eb377763b2ed9663e8949aed265b69f000f for commit
> > c59ed9b7b6d4268ae6cb1069a9b51e02ad9aa1d8
> >
> > This happens since the last `fetch --prune origin`.
> >
> > If I do it again, I get
> >
> >     $ git pull
> >     fatal: Unable to create 'C:/Users/c-flo/AppData/Roaming/Sublime
> > Text 3/Packages/GitSavvy/.git/objects/info/commit-graphs/commit-graph-chain.lock':
> > File exists.
> >     ...
> >
> > And upon removing that file, I get the first error message again.
> >
> > I actually don't know yet how to move on from here.  I'm stuck, so I
> > appreciate any help.
> >
> >     $ git --version
> >     git version 2.29.2.windows.1
> >
> >
> > Regards
> > Caspar Duregger

Thanks, Taylor

Ævar Arnfjörð Bjarmason· Nov 12, 2020, 16:27 UTC · re: Taylor Blau · lore

Re: BUG: commit-graph.c:1068 when doing `git pull`

On Thu, Nov 12 2020, Taylor Blau wrote:

Show 23 quoted lines

> Hi Caspar,
>
> On Mon, Nov 02, 2020 at 08:12:07PM +0100, herr.kaste wrote:
>> A
>>
>>     $ git commit-graph write
>>
>> did the trick.
>>
>> Let me know if you think there could be something useful to reproduce,
>> somewhere.
>
> I think this is worth trying to reproduce. The first message you're
> seeing about the commit-graph-chain.lock already existing is a
> red-herring: it's likely that the last time you tried to generate a
> commit-graph, that it hit that same BUG() and left the stale lock laying
> around. (I can't remember off the top of my head whether we still run
> the atexit handlers upon a BUG(), but even still, I could believe that
> some other stray process left it laying around, too).
>
> So, what's interesting is why your commit graph ended up in a state that
> it got some commit without all of its parents. If you could reproduce
> that state, that would be interesting.

No matter how it got to that point we shouldn't be dying on a "git pull" just because the commit-graph code had a hickup. I thought I'd addressed this in 43d3561805 ("commit-graph write: don't die if the existing graph is corrupt", 2019-03-25) and related commits, but I see that's not the case.

That code really needs to learn how to operate in two different modes. One in the write/verify codepath where we're the primary command being called, and one where we're just being called on fetch/pull/status/whatever when we shouldn't hard die just because we can't access the commit-graph side data.