Re: [PATCH 6/6] receive-pack: utilize rejected ref error details

> On Wed, Jan 14, 2026 at 04:40:47PM +0100, Karthik Nayak wrote:
>
>> In 9d2962a7c4 (receive-pack: use batched reference updates, 2025-05-19),
>> git-receive-pack(1) switched to using batched reference updates. This also
>> introduced a regression wherein instead of providing detailed error
>> messages for failed referenced updates, the users were provided generic
>> error messages based on the error type.
>>
>> Similar to the previous commit, switch to using detailed error messages
>> if present for failed reference updates to fix this regression.
>>
>> One downside of this is that the messages can be very verbose, for e.g.
>> in the files backend, when trying to write a non-commit object to a
>> branch, you would see:
>>
>>    ! [remote rejected] 3eaec9ccf3a53f168362a6b3fdeb73426fb9813d ->
>>    branch (cannot update ref 'refs/heads/branch': trying to write
>>    non-commit object 3eaec9ccf3a53f168362a6b3fdeb73426fb9813d to branch
>>    'refs/heads/branch')
>>
>> Here the refname is repeated multiple times due to how error messages
>> are propagated and filled over the code stack. This potentially can be
>> cleaned up in a future commit.
>
> If we are going to have a "potentially cleaned up in the future" state,
> I think I would prefer to see just:
>
>   if (details)
> 	rp_error("%s", details);
>
> here. And then it comes over the stderr sideband, but the actual
> status-table gets the same non-verbose message. That's what happened
> in v2.50.0 and earlier. Later if we want to try to cram more details
> into the machine-readable message we can.
>
> -Peff