Subject: Re: bug#62656: broken guix time-machine + software-heritage

From: Simon Tournier <[email-masked]>
Date: Thu, 4 May 2023 09:57:26 +0200

Hi Ludo,

On Thu, 4 May 2023 at 09:22, Ludovic Courtès <[email-masked]> wrote:

> > Even if the bug on SWH would be fixed, at the rate the Guix repo is
> > growing, it would be impractical to cook the whole Guix repo.
>
> Falling back to SWH to fetch channels is something we expect to be rare,
> though.

Being rare will not make it practical. ;-)

What I am trying to point is that considering the size of the Guix
repository and its rate, the current implementation will not scale and
the fallback will be impossible for the end-user.

> > And it appears to me weird when we, most of the time, need a very
> > restricted set of commits.
> >
> > We could imagine to locally create a new repo (git init) and only add
> > the content of the commit specified by “guix time-machine”.
>
> To do that we’d need to say goodbye to the features I mentioned above.

Well, I do not see which features will be missing.  I am talking about
making practical:

    guix time-machine -C channels.scm -- shell -m manifest.scm

and not having a complete working Guix.  Well, I read a paper that
mentions this command line, I want to inspect so I am running this
command.  Somehow, I do not care about the others 114456 commits of
the history.  And for sure "guix time-machine -C channels.scm --
describe -f channels" will not be a fixed-point.

Maybe, we could imagine an option for shortcutting the complete clone
and restrict to one specific commit.

Cheers,
simon