Re: [PATCH v3 0/6] refs: provide detailed error messages when using batched update

> The refs namespace uses an error buffer to capture details about failed
> reference updates. However when we added batched update support to
> reference transactions, these messages were never propagated, instead
> only an error code pertaining to the type of failure was propagated.
>
> Currently, there are three regions which utilize batched updates:
>
>   - git update-ref --batch-updates
>   - git fetch
>   - git receive-pack
>
> While 'git update-ref --batch-updates' was a newly introduced flag, both
> 'git fetch' and 'git receive-pack' were pre-existing. Before using
> batched updates, they provided more detailed error messages to the user,
> but this changed with the introduction of batched updates. This is a
> regression in their workings.
>
> This patch series fixes this, by passing the detailed error message and
> utilizing it whenever available. The regression was reported by Elijah
> Newren [1] and based on the patch submitted by Jeff King [2].
>
> [1]: https://lore.kernel.org/all/CABPp-BGL2tJR4dPidQuFcp-X0_VkVTknCY-0Zgo=jHVGv_P=wA@mail.gmail.com/
> [2]: https://lore.kernel.org/all/20251224081214.GA1879908@coredump.intra.peff.net/
>
> ---
> Changes in v3:
> - Drop the first commit.
> - For the last commit, where we delay 'git fetch' status information,
>   delay all information to the end. Also use a list to compliment the
>   existing strmap, this ensures that the order is maintained.
> - Link to v2: https://patch.msgid.link/20260116-633-regression-lost-diagnostic-message-when-pushing-non-commit-objects-to-refs-heads-v2-0-925a0e9c7f32@gmail.com