bug#69058: Failure when fallback to Disarchive+SWH

[Ludovic Courtès]

Hi,

Simon Tournier <zimon.toutoune@gmail.com> skribis:

>> Fixed in 1610a632d4b3097282d18af27ff3e9e178d7dfcb.
>
> Cool!  Thanks.
>
> However, it means that it stays broken for all commits before this fix,
> right?  Somehow, if only SWH is available, then
>
>     guix time-machine -C channels.scm -- shell -m manifest.scm
>
> will fail for all channels older than today.  Right?

Mostly, yes (“mostly” because derivations using “builtin:git-download”
will automatically be fixed once we’ve updated the ‘guix’ package, but
that only helps if you’re traveling to after September 2023 (commit
13b0cf85eb31e1b1ea674debbbfb0f35a32d1374).

> For instance, redoing your ReScience paper from 2020 using only SWH as I
> did [1] some months ago is now broken (because a change on SWH side).

Indeed.  :-/

That’s a real bummer, but that’s the nature of software: we cannot
retroactively fix bugs.

> Well, I am fine to keep this bug closed but for the posterity we need
> something like:
>
>     guix swh get -C channels.scm -m manifest.scm

Exactly!  We have the demonstration of just how important that is.

Ludo’.