bug#55898: Services depending on new Shepherd features may fail until reboot

[Ludovic Courtès]

Hi Maxim,

Maxim Cournoyer <maxim.cournoyer@gmail.com> skribis:

> Agreed, but the context differs wildly: while Autoconf or browsers for
> example really are facing a diversity of configuration, the version of
> Shepherd used in Guix System is known and controlled.  So the only
> problems bound to happen are in this context:
>
> 1. New Shepherd version introduced in Guix (package upgrade).
>
> 2. New Shepherd features used by services.
>
> 3. Machine reconfigured using a commit including 1 and 2.
>
> The problems are temporary: upon a reboot the running Shepherd version
> will be the latest, and have all the features needed.
>
> Hence my suggestion to use something simple to improve the user
> experience of a user faced with 3.

So are you suggesting replacing:

  (defined? 'make-inetd-constructor)

by something like:

  (version<? shepherd-version "0.9.0")

or is it something different that you have in mind?

I’m not sure how this could improve the user experience, unless by
“user” you mean the person writing the service?

Thanks,
Ludo’.