Orestis Floros [off-list ref] writes:
...
The latter used to be the only symptom. Before bb5da75d61 (commit: use
commit graph in `lookup_commit_reference_gently()`, 2026-02-16) the
initial lookup did not record commit-graph positions, so the walk simply
failed to find the submodule commits in the superproject:
error: Could not read <commit>
Failed to merge submodule sub (commits don't follow merge-base)
Pass the repository into both functions. git-fetch-pack(1) and
git-upload-pack(1) keep passing `the_repository`.
That's reasonable. It is a very welcome change that aligns with
recent libification efforts.
Will queue.
Thanks.