So I don't think this is some clever or subtle behavior, but just a bug
in 4f37d45706 (clone: respect remote unborn HEAD, 2021-02-05).
[snip]
But the unborn case has
an additional side effect of calling create_symref(), and we want that
to happen whether we are bare or not.
Thanks for the analysis. Indeed, I missed the fact that we need the
create_symref() side effect whether the repository is bare or not.
Reviewed-by: Jonathan Tan <redacted>