bug#62216: Narrowed the issue to one line

[Eli Zaretskii]

> Date: Sun, 20 Aug 2023 14:13:25 -0500
> Cc: 62216@debbugs.gnu.org
> From: Paul Eggert <eggert@cs.ucla.edu>
> 
> On 8/20/23 10:26, Eli Zaretskii wrote:
> 
> > Po Lu, Paul: any idea why that could be the case in the OP's scenario?
> > The only thing that comes to my mind is some weirdness of the OP's
> > filesystem.
> 
> I don't see even that. What sort of weirdness did you have in mind?

Something that affects 'seekable', perhaps?  It's far-fetched, I know.
But what else could be at work here?