bug#50982: [PATCH] scripts: home/system: Don’t throw an error if no generations exist.

[Ludovic Courtès]

Maxime Devos <maximedevos@telenet.be> skribis:

> Xinglu Chen schreef op za 02-10-2021 om 23:05 [+0200]:
>> Previously, When running ‘guix home describe’ or ‘guix system describe’ prior
>> to having any generations, a backtrace would produced.  Since not having any
>> existing generations is not an error, a warning would be enough.
>> 
>>   $ guix system describe
>>   guix system: warning: no system generation, nothing to describe
>
> Printing a warning instead of an error to avoid a backrace isn't necessary.
> E.g., "guix show i-do-not-exists" prints an error
> ‘guix show: error: i-do-not-exist: package not found’.
>
> I suggest using (leave (G_ "bla bla")) instead of (error (G_ "bla bla"))
> for these kind of errors, it appears to work '%find-package' in (gnu 
> packages).

I’ve done that now, thanks!

Ludo’.