Re: Incremental 'git fetch' downloaded everything again
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jul 7, 2026, 22:51 UTC
- Message-ID
- <xmqqh5maza5g.fsf@gitster.g>
- In-Reply-To
- <ak1+dsNQIV8EeSIc@szeder.dev>
SZEDER Gábor <szeder.dev@gmail.com> writes:
Show 15 quoted lines
> I usually try to fetch from https://github.com/git/git daily, and > today morning something unusual happened: > > $ git fetch > remote: Enumerating objects: 406099, done. > remote: Counting objects: 100% (1229/1229), done. > remote: Compressing objects: 100% (1044/1044), done. > remote: Total 406093 (delta 207), reused 1189 (delta 185), pack-reused 404864 (from 2) > Receiving objects: 100% (406093/406093), 292.22 MiB | 4.62 MiB/s, done. > Resolving deltas: 100% (308943/308943), done. > From https://github.com/git/git > + ffe2b816f5...106a830b98 jch -> origin/jch (forced update) > e9019fcafe..f85a7e6620 master -> origin/master > + c42f45431d...00534a21ce next -> origin/next (forced update) > + f6884212b2...73452939f9 seen -> origin/seen (forced update)
The only difference I can think of is that 'next' has been rewound recently, but because 'seen' and 'jch' are constantly reound, it would be very strange that it made such a big difference.
So, sorry, no idea. If I were bug-hunting this, I would first try to eliminate whatever GitHub runs on their server end from the picture.
Show 30 quoted lines
> Note that it downloaded over 400k objects in an almost 300MB packfile.
>
> Looking at the objects that I already had and the objects in the newly
> downloaded packfile:
>
> $ git rev-list --objects origin/master@{1} origin/next@{1} origin/jch@{1} origin/seen@{1} | cut -d' ' -f1 | sort >existing-objects
> $ git verify-pack -v .git/objects/pack/pack-080fedc9c19f711dd1b22103b382ede8925b90a6.idx | sed -n -E -e 's/^([0-9a-f]{40}) .*/\1/p' | sort >received-objects
> $ wc -l existing-objects received-objects
> 406954 existing-objects
> 406093 received-objects
> 813047 total
> $ git diff --no-index --stat existing-objects received-objects
> existing-objects => received-objects | 3615 +++++++++++++---------------------
> 1 file changed, 1377 insertions(+), 2238 deletions(-)
>
> The vast majority of objects were already available locally.
>
> What's going on?!
>
> This might be a recurring issue: I remember a similar large download
> from 2 or 3 weeks ago, but back then I didn't have time to investigate
> or to report.
> I tried to reproduce this issue by attempting to recreate the state of
> my git repository from yesterday in a new repo, but no luck, 'git
> fetch' only downloads what's necessary.
>
> I use a Git version based on next, with a bunch of my own patches on
> top, but none of them has anything to do with object transfer and I've
> been using most of them for years. I don't have any config set under
> 'fetch.*' or 'transfer.*'.