Re: Towards reproducibly Jupyter notebooks with Guix-Jupyter

["Ludovic Courtès" <ludovic.courtes@inria.fr>]

Hi Konrad,

Konrad Hinsen <konrad.hinsen@fastmail.net> skribis:

>> Depending on the use case, another option is to not use inferiors at all
>> and simply do:
>>
>>   guix pull --commit=XYZ -p ./my-old-guix
>>   ./my-old-guix/bin/guix environment --ad-hoc whatevern
>>
>> But maybe I’m missing something, let me know.  :-)
>
> That was my starting point. It's OK for manual execution, but if I want
> an Org-Mode file to this automatically, I need to generate a temporary
> file in place of ./my-old-guix with all the associated hassles: check
> that it doesn't exist before, and clean up in the end even in the case
> of errors. Maybe I'd even have to worry about two processes accessing
> the same temporary file and do some locking.

I see.  In a way one could argue that it’s not Guix’ problem, but OTOH
it’s clearly a problem that Guix doesn’t make it more convenient.

> I ended up finding an approach that does work, though it relies on
> undocumented properties:
>
>    (use-modules (guix channels)
>                 (guix inferior))
>
>    (define channels
>      (list (channel
>             (name 'guix)
>             (url "https://git.savannah.gnu.org/git/guix.git")
>             (commit
>              "44881cad93801de9462d469500d582af79b99959"))))
>
>    (define inferior
>      (inferior-for-channels channels))
>
>    (define inferior-executable
>      (inferior-eval
>       '(car (program-arguments))
>       inferior))
>
>    (define inferior-command-line
>      (cons inferior-executable (cdr (program-arguments))))
>
>    (apply system* inferior-command-line)
>
> This script uses the inferior mechanism for creating and caching an
> older guix, but then calls its executable directly.
>
> Of course this idea could be implemented in a better way, by factoring
> out the caching mechanism from inferior-for-channels and providing a
> command-line interface. Something like
>
>    guix time-machine channels.scm command args ...
>
> Does this sound reasonable? I volunteer for implementing this, but I'd
> like to have an expert opinion first.

That sounds reasonable to me: it’s a simple and easily-understood UI
(easier than the ‘guix pull -p’ dance!), and the implementation should
be easy (thus the maintenance cost is very low).

Looking forward to a patch!  :-)

Thank you,
Ludo’.