From: Jeff King <peff@peff.net>
Date: Mon, 28 Sep 2026 04:05:11 GMT
Subject: Re: [PATCH] p5551: fix repeated runs with update-ref --no-deref
Message-ID: <20260928040511.GA498426@coredump.intra.peff.net>
In-Reply-To: <20260926180648.60770-1-jon@jonsimons.org>

On Sat, Sep 26, 2026 at 02:06:48PM -0400, Jon Simons wrote:

> Update p5551-fetch-rescan.sh to pass `--no-deref` when deleting child
> test refs before each measured `git fetch`.  Otherwise, for repeated
> runs, the second iteration will fail with:
> 
>     fatal: multiple updates for 'refs/remotes/origin/master' (including
>     one via symref 'refs/remotes/origin/HEAD') are not allowed
> 
> Starting with 3f763ddf28 (fetch: set remote/HEAD if it does not exist,
> 2024-11-22), `git fetch` instantiates the HEAD symref.
> 
> The test, introduced in 7893bf1720 (p5551: add a script to test fetch
> pack-dir rescans, 2017-11-20), predates that.

Thanks, the explanation and patch both make sense.

This test could probably benefit from using --setup (which also didn't
exist back when this test was written). But that's nothing new, and well
outside the scope of your patch.

-Peff