Re: [PATCH 0/3] fsck index files from all worktrees

> On Sat, Feb 18, 2023 at 10:38:33AM +0100, Johannes Sixt wrote:
> 
>> I see three problems here:
>>
>> - git fsck should detect the problem (if it really is one) in the
>> worktree index. It seems that it is just an index extension that is
>> affected. Perhaps it should be just a warning, not an error.
> 
> We do fsck the resolve-undo extension, but I think fsck just doesn't
> know anything about worktrees. That should be easy enough to fix.
> Patches below.
> 
>> - If the objects mentioned in the index extension are precious, they
>> should not have been garbage-collected in earlier rounds of git gc
>> (which I certainly did at some point).
> 
> Correct, but the gc error you're getting indicates that we _are_ trying
> to treat them as included. I wonder if you ran git-gc long ago with an
> older version of Git, and this breakage was waiting to surface. AFAICT
> this was all fixed by 8a044c7f1d (Merge branch 'nd/prune-in-worktree',
> 2017-09-19).

>> - I can't git gc the repository now, which is particularly annoying when
>> auto-gc is attempted after almost every git command. Of course, I know
>> how to get out of the situation, but it took some time to identify the
>> worktree index as the culprit. Not something that a beginner would be
>> able to do easily.
> 
> I think in general that "oops, there's something corrupt" can be hard to
> get out of, just because there are so many possibilities. But if we can
> at least report the nature of the problem and the offending filename via
> git-fsck, that would help with pointing people in the right direction.