bug#74015: 'guix shell --export-manifest' fails for some transformations

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

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

> On Sun, 10 Nov 2024 at 12:38, Ludovic Courtès <ludo@gnu.org> wrote:
>
>>> $ guix shell -m manifest.scm --export-manifest
>>
>> ‘--export-manifest’ is meant to “translate” a command line, which it can
>> do faithfully; there’s no way it could possibly “recreate” what
>> ‘manifest.scm’, which may contain arbitrary Scheme code (and someone who
>> already has a ‘manifest.scm’ file probably doesn’t need
>> ‘--export-manifest’).
>
> Yes, one might need. :-)
>
> As I explained: « That’s annoying in some context as “guix pack
> --save-provenance” [1].  Even, it defeats the idea of a self-contained
> reproducible binary container. »

I see, but if you have the source ‘manifest.scm’, best practice is to
publish it.

>> It’s necessarily a lossy process.
>
> This is where I disagree. :-)

You are free to disagree but it’s a fact.

> I mean, yes I agree that building profile/manifest is somehow a lossy
> process because some Scheme is potentially evaluated on the road.
> However, I am proposing: Aside the profile ’manifest’ file (lossy
> process), we could store all the manifests provided by the command
> line.  Something as:
>
>     /gnu/store/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-profile/manifest
>     /gnu/store/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-profile/manifest.orig1
>     /gnu/store/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-profile/manifest.orig2
>     …
>
> where manifest.orig1 and manifest.orig2 are the copy of files ’foo.scm’
> and ’bar.scm’ from:
>
>     -m foo.scm -m bar.scm

Hmm yes, maybe ‘guix pack -m manifest.scm --save-provenance’ could
arrange to put ‘manifest.scm’ inside the pack, similar to how ‘guix
system reconfigure’ inserts ‘configuration.scm’ inside the system.

I’m all for it!

Thanks,
Ludo’.