Re: [BUG] Lazy fetch in partial clone fails with "not our ref" since 5946a564 (odb/source: make read_object_info() pluggable)

From: Patrick Ohly <patrick.ohly@intel.com>
Date: Nov 4, 2026, 11:56 UTC
Message-ID: <yrjhld78q06y.fsf@pohly-mobl1.fritz.box>
In-Reply-To: <CAL71e4MqMdGk5ryhNxvVNN6Z02+45B933ZfUuvj4hM92N5a6hA@mail.gmail.com>

Kristofer Karlsson <krka@spotify.com> writes:

Show 24 quoted lines

> On Tue, 3 Nov 2026 at 14:31, Patrick Ohly <patrick.ohly@intel.com> wrote:
>>
>> Hello,
>>
>> "git merge" in a blobless partial clone fails with "not our ref" while
>> lazily fetching a missing object. This started to occur today in the
>> Kubernetes CI, completely breaking the merging of PRs. We should have
>> been using git 2.54.0, the affected version, for a few days at least
>> without issues, so it can't be ruled out that this is at least partly
>> caused by a change on the GitHub side. We are about to revert to git
>> 2.52.0 to unblock the Kubernetes project.
>>
>> [...]
>>
>> I bisected v2.52.0 (good) to v2.54.0 (bad). The first bad commit is:
>>
>> 5946a564cddc0bf471f27ae4c3fe205441e3ef65
>> odb/source: make `read_object_info()` function pluggable
>>
>> The parent, 3bc3177ad7 ( 2.53.0.185.g3bc3177ad7 ), is good.
>
> Thanks for the detailed report.  I think I have found the cause: I
> can reproduce the failure with your steps and make it go away with a
> small change to the loose object cache.

Any idea why this suddenly started to occur?

We were using 2.54.0 for several days without issues prior to the failure. For example, https://storage.googleapis.com/kubernetes-ci-logs/pr-logs/pull/batch/pull-kubernetes-cmd/2117551425255903232/clone-log.txt merged several different PRs for https://prow.k8s.io/view/gs/kubernetes-ci-logs/pr-logs/pull/batch/pull-kubernetes-cmd/2117551425255903232 using us-docker.pkg.dev/k8s-infra-prow/images/clonerefs:v20261028-c06373a3e as environment. It contains 2.54.0.

-- 
Best Regards

Patrick Ohly
Cloud Software Architect