Subject: bug#76698: Activations interfere with each other modules

From: Tomas Volf <[email-masked]>
Date: Mon, 17 Mar 2025 22:36:37 +0100

Ludovic Courtès <[email-masked]> writes:

> Hello,
>
> Hilton Chain <[email-masked]> skribis:
>
>> Activation scripts are already ‘program-file’s, but unfortunately
>> (gnu build activation) and (guix build utils) are implicit dependencies.  This
>> is hard to change at the moment.
>>
>> I have sent a patch which might partially address your issue:
>>
>> [PATCH v2 3/3] services: activation: Continue on exceptions.
>> https://issues.guix.gnu.org/73494#26
>>
>> It executes activation scripts by ‘invoke’, so they won't change the
>> environment.
>
> Activation snippets all run in the same Guile process so far, mostly out
> of a concern to be more efficient than running each one in a separate
> process as you suggest.
>
> The downside is what Tomas found out: the load path is global to the
> entire set of activation snippets.
>
> Now, maybe we could have the best of both worlds: instead of
> ‘activation-script’ doing
>
>   (for-each primitive-load '#$actions)
>
> it could do something like:
>
>   (for-each (lambda (action)
>               (guard …   ;like Hilton suggests
>                 (save-module-excursion
>                   (lambda ()
>                     (set-current-module (resolve-module '(guile-user)))
>                     (primitive-load action)))))
>             '#$actions)
>
> Thoughts?

+1 for the approach, for implementation I think you need
(make-fresh-user-module) instead of (resolve-module '(guile-user)).

> Ludo’.

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