bug#63979: bug#64119: [PATCH] services: shepherd: Sanitize 'provision' field.

[Ludovic Courtès]

Bruno Victal <mirai@makinata.eu> skribis:

> +(define (sanitize-shepherd-service-provision expr)
> +  (match expr
> +    (((? symbol?) ..1) expr)
> +    (_
> +     (raise
> +      (formatted-message
> +       (G_ "'provision' must be a non-empty list of symbols"))))))

Actually I figured we could do as in other areas of the code in a way
that reports error location, so I came up with a different patch.

Ludo’.