Ludovic Courtès <ludo@gnu.org> writes:

> Christopher Baines <mail@cbaines.net> skribis:
>
>> Mark H Weaver <mhw@netris.org> writes:
>
> [...]
>
>>>> +(define-gexp-compiler (gitolite-rc-file-compiler
>>>> +                       (file <gitolite-rc-file>) system target)
>>>> +  (match file
>>>> +    (($ <gitolite-rc-file> umask git-config-keys roles enable)
>>>> +     (apply text-file* "gitolite.rc"
>>>> +      `("%RC = (\n"
>>>> +        "    UMASK => " ,(format #f "~4,'0o" umask) ",\n"
>
> [...]
>
>>> --8<---------------cut here---------------start------------->8---
>>>            0 (simple-format #f "~4,'0o" 63)
>>>
>>> ERROR: In procedure simple-format:
>>> In procedure simple-format: FORMAT: Unsupported format option ~4 - use (ice-9 format) instead
>>> --8<---------------cut here---------------end--------------->8---
>
> [...]
>
>> It sounds to me like adding #:use-modules (ice-9 format) to (gnu
>> services version-control) would fix this, but I'll wait until I can
>> reproduce the failure before re-adding the service.
>
> Yes, adding #:use-module (ice-9 format) will fix the problem.
>
> You should be able to reproduce it by running “make hydra-jobs”.
>
> As to why you can’t necessarily reproduce it…  It turns out that loading
> (ice-9 format) has the effect of set!ting the global ‘format’ binding.
> So if some unrelated piece of code loads (ice-9 format), you don’t have
> any problems; but if that doesn’t happen, you get the error.
>
> This terrible behavior has been in Guile forever and nobody has dared
> changing it so far.  :-)  The -Wformat warning tries hard to diagnose
> the issue though.

Thanks both. I've added the #:use-module (ice-9 format) bit, and pushed
now. Locally I got make hydra-jobs.scm to run successfully, so hopefully
this hasn't broken anything this time :)

Chris