Renovate git-submodules: Annotated tags not updated, with "empty commit" warnings printed in the logs

[jasonlearst]

How are you running Renovate?

Self-hosted Renovate

Which platform you running Renovate on?

Gitea

Which version of Renovate are you using?

42.74.2

Please tell us more about your question or problem

I had enabled updating of git-submodules on my repository

    "git-submodules": {
        "enabled": true
    },

Renovate Bot ran and created PRs for all of the submodules in my project pointing to the latest commits in the repositories. After reading the documentation further I updated my .gitmodules file with branch=<tag> for each of the submodules to have Renovate Bot only update each of the submodules to the latest semver tags.

Renovate Bot closed all of the open PRs (since the submodules were already on the correct commits) except for the https://github.com/ansible-collections/ansible.posix.git submodule. Here Renovate Bot aborted with: ⚠️ WARN: Detected empty commit - aborting git push.

I have created a minimal reproduction here: https://github.com/jasonlearst/detected-empty-commit-renovate-minimal-reproduction.

Logs (if relevant)

Logs

[{"branchName":"main","sha":"7a7e66900a93a02c1883ad4fb8edc8b57889ed91"}],"branches":[{"automerge":false,"baseBranch":"main","baseBranchSha":"7a7e66900a93a02c1883ad4fb8edc8b57889ed91","branchName":"renovate/ansible-posix-digest","branchSha":"b165cc974f257222d8d879c41a1f514aedf6bfaf","isModified":false,"isPristine":false}],"defaultBranch":"main","inactiveBranches":[],"msg":"Branch summary","time":"2026-01-10T02:16:17.120Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","branchesInformation":[{"branchName":"renovate/ansible-posix-digest","prNo":2,"prTitle":"Update ansible-posix digest to a8c076a","result":"done","upgrades":[{"datasource":"git-refs","depName":"ansible-posix","displayPending":"","fixedVersion":"2.1.0","currentVersion":"2.1.0","currentValue":"2.1.0","currentDigest":"e54b8bf68f583f2324861a8cb113d4f1bb20f3de","newValue":"2.1.0","newDigest":"a8c076a575ec98cc15314cefe39b09fe87a4d625","packageFile":".gitmodules","updateType":"digest","packageName":"https://github.com/ansible-collections/ansible.posix.git"}]}],"msg":"branches info extended","time":"2026-01-10T02:16:17.121Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","stats":{"total":1,"open":1,"closed":0,"merged":0},"msg":"Renovate repository PR statistics","time":"2026-01-10T02:16:17.121Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","msg":"Repository result: done, status: onboarded, enabled: true, onboarded: true","time":"2026-01-10T02:16:17.121Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","repoProblems":["⚠️ WARN: Detected empty commit - aborting git push"],"msg":"repository problems","time":"2026-01-10T02:16:17.122Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","splits":{"init":2032,"onboarding":1,"extract":1152,"lookup":240,"update":2306},"total":6823,"msg":"Repository timing splits (milliseconds)","time":"2026-01-10T02:16:17.187Z","v":0}
{"name":"renovate","hostname":"jr-microvm","pid":692,"level":20,"logContext":"h_AkjwJeUzYhlb8HjhiFe","repository":"jasonlearst/detected-empty-commit-renovate-minimal-reproduction","get":{"count":1,"avgMs":4,"medianMs":4,"maxMs":4,"totalMs":4},"set":{"count":0,"avgMs":0,"medianMs":0,"maxMs":0,"totalMs":0},"msg":"Package cache statistics","time":"2026-01-10T02:16:17.187Z","v":0}

[G00fY2]

Issue also happens with 43.0.5. We see the same behavior in our project. It seems like Renovate tries to add a digest to the version, which is afaik not supported.

[jasonlearst]

git ls-remote returns 2 hashes where there is an annotated tag.

[I] ~/D/d/ansible-posix ((2.1.0)|✔) $ git ls-remote | grep refs/tags/2.1.0
From https://github.com/ansible-collections/ansible.posix.git
a8c076a575ec98cc15314cefe39b09fe87a4d625        refs/tags/2.1.0
e54b8bf68f583f2324861a8cb113d4f1bb20f3de        refs/tags/2.1.0^{}

I think Renovate explicitly skips the references ending with ^{}.

renovate/lib/modules/datasource/git-refs/base.ts

Line 69 in 39dbc07

.filter((ref) => ref.type !== 'pull' && !ref.value.endsWith('^{}'));

In my example since the submodule is on the commit e54b8bf6 Renovate decides that there is a new digest.

"currentValue":"2.1.0","currentDigest":"e54b8bf68f583f2324861a8cb113d4f1bb20f3de","newValue":"2.1.0","newDigest":"a8c076a575ec98cc15314cefe39b09fe87a4d625"

But since a8c076a5 is only a tag and not a commit, there is nothing to update the submodule to (as it should be pinned to the commit e54b8bf6).

[I] ~/D/d/ansible-posix ((2.1.0)|✔) $ git show a8c076a5
tag 2.1.0
Tagger: saito-hideki <saito@fgrep.org>
Date:   Thu Jul 17 09:11:39 2025 +0900

Release 2.1.0

commit e54b8bf68f583f2324861a8cb113d4f1bb20f3de (HEAD, tag: 2.1.0)
Merge: 9d3cb96 d792d39
Author: softwarefactory-project-zuul[bot] <33884098+softwarefactory-project-zuul[bot]@users.noreply.github.com>
Date:   Thu Jul 17 00:01:11 2025 +0000

    Merge pull request #658 from saito-hideki/release_2.1.0

    Release 2.1.0 commit

    SUMMARY
    Release 2.1.0 commit

    Release Plan #149

    ISSUE TYPE

    Feature Pull Request

    COMPONENT NAME

    ansible.posix

    ADDITIONAL INFORMATION
    This will be merged on 17 July if there are no problems

    Reviewed-by: Felix Fontein <felix@fontein.de>
    Reviewed-by: Andrew Klychkov <aklychko@redhat.com>