Re: [PATCH -v2 2/2] guix: profiles: create fonts.dir/scale for all fonts directories

[Ludovic Courtès]

huang ying <address@hidden> skribis:

> On Wed, Mar 8, 2017 at 4:24 AM, Danny Milosavljevic
> <address@hidden> wrote:
>> Hi,
>>
>>> +                            (with-directory-excursion dir
>>> +                              (and (file-exists? fonts-scale-file)
>>> +                                   (delete-file fonts-scale-file))
>>> +                              (and (file-exists? fonts-dir-file)
>>> +                                   (delete-file fonts-dir-file))
>>> +                              (system* mkfontscale)
>>> +                              (system* mkfontdir)
>>
>> Please do not throw away the status code here (result of system*). You can 
>> check for okayness by (zero? (system* ...)).
>
> Then what is the intended behavior?  abort the build process with
> message and non-zero exit code?  Usually we will raise a exception or
> just display some message and exit?

See for instance ‘info-dir-file’, which does this:

          (exit (every install-info
                       (append-map info-files
                                   '#$(manifest-inputs manifest))))

The effect is to exit with 0 upon success and some other code upon
failure, leading to a proper derivation build failure.

HTH!

Ludo’.