Re: ’guix package --export-manifest’ using ’@version’?

["Ludovic Courtès" <ludo@gnu.org>]

Hi,

zimoun <zimon.toutoune@gmail.com> skribis:

> $ guix package -p gnu/store/vmn2b3cmfwf250i65rgvkamyr4971q7m-profile \
>        --export-manifest
> ;; This "manifest" file can be passed to 'guix package -m' to reproduce
> ;; the content of your profile.  This is "symbolic": it only specifies
> ;; package names.  To reproduce the exact same profile, you also need to
> ;; capture the channels being used, as returned by "guix describe".
> ;; See the "Replicating Guix" section in the manual.
>
> (specifications->manifest
> (list "python@3.8" "python-numpy@1.17"))

[...]

> The export of the versions depending on the state appears to me
> confusing; for newcomers or people from the classical package managers.
> And it provides more work when transitioning from imperative to
> declarative.
>
>
> Therefore, I think ’--export-manifest’ should not report the version and
> it should be stateless.  However, we could add a comment about
> “--export-channels”.

(Nitpick: it *is* stateless, in the sense that it only depends on Guix
itself, not on the state of the machine where it is being run.)

I see what you mean, but I disagree with the conclusion.

‘--export-manifest’ emits a comment (shown above) explaining that the
manifest is symbolic and that one needs channel info to replicate the
exact same environment.

It is a departure from traditional package managers, and admittedly
surprising to newcomers.  However, my take on this is that we should be
very upfront about symbolic vs. exact reproducibility.  We would muddy
the waters if we gave version strings the same importance as in other
tools, when we know that a version string means very little.

Thoughts?

Ludo’.