Re: Reverse dependencies

[Eric Bavier <ericbavier@openmailbox.org>]

On 2016-08-12 11:24, Chris Marusich wrote:
> Eric Bavier <ericbavier@openmailbox.org> writes:
> 
>> On 2016-08-11 09:43, Vincent Legoll wrote:
>>> Hello,
>>> 
>>>>> I'm trying to understand which package(s) depends on some other
>>>>> package,
>>>>> kind of the reverse of what guix graph does (I think).
>>>> 
>>>> I think that `guix refresh --list-dependent foo` is what you are
>>>> asking
>>>> for, or at least it's close. We use it to learn what will need to be
>>>> rebuilt when upgrading foo.
>>> 
>>> Not really what I want to know:
>>> 
>>> # guix refresh --list-dependent inkscape
>>> Building the following 5 packages would ensure 10 dependent packages
>>> are rebuilt: frescobaldi-2.19.0 solfege-3.22.2 simple-scan-3.19.91
>>> termite-11 hydra-20150407.4c0e3e4
>>> 
>>> None of those are installed, but inkscape is pulled in by something
>>> which I want to know
>>> 
>>> Is there no other way to get that information ?
>> 
>> Something like (mildly tested):
>> 
>> (use-modules (guix packages)
>>              (gnu packages)
>>              (gnu packages inkscape)
>>              (srfi srfi-1)
>>              (srfi srfi-26))
>> 
>> (fold-packages
>>   (lambda (package _)
>>     (when (any (cut eq? <> inkscape)
>>                (map second (package-direct-inputs package)))
>>       (format #t "~a depends on inkscape~%"
>>               (package-full-name package))))
>>   #t)
>> 
>> which, when run, results in:
>> "dblatex-0.3.5 depends on inkscape"
> 
> The 'guix graph' command has the ability to print out references, but 
> my
> understanding is that because these are the references which result 
> from
> Nix's scan of the output store path, these references will only be
> runtime dependencies (see '(guix) Invoking guix graph' in the manual).

This is not completely accurate.  'guix graph's '--type' argument can be 
used to display different node types.  The 'references' type corresponds 
to run-time dependencies.

-- 
`~Eric