Hey Maxim,

Sound like a fine plan.

> 1.  Promptly set up both a blog post and a NEWS entry announcing the
> support for gzip substitutes is about to be phased out from the build
> farm (1 month notice), urging users to upgrade their daemon to a version
>>= 1.1.0.

I addition, we could warn users with old daemons as proposed by Ludo &
Ricardo. There's an attached patch here.

> -                   ;; TODO: Eventually, disable gzip, as discussed at
> -                   ;; <https://lists.gnu.org/archive/html/guix-devel/2021-03/msg00333.html>.
> -                   (compression '(("gzip" 9) ("lzip" 9) ("zstd" 19)))
> +                   (compression '(("lzip" 9) ("zstd" 19)))
>                     (cache-bypass-threshold cache-bypass-threshold)
>                     (workers publish-workers)))

Nice.

> 3. Come up with a Guile script that is able to
>
>   a) Strip gzip-related metadata from the .narinfo guix-publish metadata
>   files
>   b) recompute and update their 'Signature' field.
>
> 4. Finally, 'rm -r /var/guix/publish/gzip' and free about 6.5 TiB of data.

I hope the script will be able to complete within a reasonable amount of
time, but we cannot know before trying it out :).

Thanks,

Mathieu