From: Mirochnik, Oleg V <oleg.v.mirochnik@intel.com>
Date: Wed, 25 Dec 2024 17:23:13 GMT
Subject: "git fetch" fails for a --reference clone after an outer forced push
Message-ID: <SJ0PR11MB581445B096273126D18F3724C60C2@SJ0PR11MB5814.namprd11.prod.outlook.com>

Hi all,

To reduce traffic, we use local mirrors via "git clone --reference mirror ..." commands.
And we regularly get problems with update of few weeks old clones and must run something like below to get rid of outdated branches:

git for-each-ref --format="%(refname)" | while read ref; do
    git show-ref --quiet --verify $ref 2>/dev/null || git update-ref -d $ref
done

This can be quite long operation as number of refs is significant.

Details are below.

Thanks,
Oleg.


Thank you for filling out a Git bug report!
Please answer the following questions to help us understand your issue.

What did you do before the bug happened? (Steps to reproduce your issue)

$ cat ./doit
#!/bin/sh
set -xe
rm -rf tst
mkdir tst
cd tst
mkdir master
git -C master init --bare
git clone master local
touch local/foo
git -C local add .
git -C local commit -m init-commit
git -C local push
echo foo > local/foo
git -C local commit -a -m dummy-commit
git -C local push origin HEAD:refs/heads/dummy
git clone --mirror file://`pwd`/master mirror
git clone --reference `pwd`/mirror file://`pwd`/master local1
git -C local1 log --oneline origin/dummy
git -C local commit --amend -m new-dummy-commit
git -C local push -f origin HEAD:dummy
git -C mirror fetch
git -C mirror gc --prune=now
git -C local1 fetch
git -C local1 log --oneline origin/dummy

What did you expect to happen? (Expected behavior)

No errors; last few lines like:

+ git -C local1 fetch
From file:///tmp/tst/master
 + 552a293...248c7fa dummy      -> origin/dummy  (forced update)
+ git -C local1 log --oneline origin/dummy
248c7fa (origin/dummy) new-dummy-commit
0636429 (HEAD -> master, origin/master, origin/HEAD) init-commit

What happened instead? (Actual behavior)

+ git -C local1 fetch
fatal: bad object refs/remotes/origin/dummy
error: file:///tmp/tst/master did not send all necessary objects

What's different between what you expected and what actually happened?

Obvious - should work and does not work

Anything else you want to add:

It works if "git -C mirror gc --prune=now" step is skipped or if local path is used for the clone steps instead of the "file://"
The same issue is with https://github.com/...
The same issue if use "git -C local1 remote update --prune" instead of the "git -C local1 fetch"

Please review the rest of the bug report below.
You can delete any lines you don't wish to share.

podman ub24 container is used to get a newer git version.
Exactly the same behavior is for the git v2.39.1

[System Info]
git version:
git version 2.43.0
cpu: x86_64
no commit associated with this build
sizeof-long: 8
sizeof-size_t: 8
shell-path: /bin/sh
uname: Linux 5.14.0-70.13.1.el9_0.x86_64 #1 SMP PREEMPT Thu Apr 14 12:42:38 EDT 2022 x86_64
compiler info: gnuc: 13.2
libc info: glibc: 2.39
$SHELL (typically, interactive shell): <unset>


[Enabled Hooks]
not run from a git repository - no hooks to show