Re: [PATCH] profiles: Add 'hicolor' and 'HighContrast' icon theme hooks.

[ludo@gnu.org (Ludovic Courtès)]

宋文武 <iyzsong@gmail.com> skribis:

> Ludovic Courtès <ludo@gnu.org> writes:
>
>> 宋文武 <iyzsong@gmail.com> skribis:

[...]

>>>> +    (gexp->derivation (string-append (string-downcase name) "-icon-theme")
>>>> +                      build
>>>> +                      #:modules '((guix build utils)
>>>> +                                  (guix build union))
>>>> +                      #:local-build? #t)))
>>> When to exclude this derivation?
>>>
>>> 1. the best would be whether icon dir exists or not
>>>    but is this posibble to implement? and how?
>>
>> Currently this is not possible.  The builder could depend on all the
>> manifest entries and scan them for share/icons directory, but at this
>> point it’s already too later because the build has to depend on GTK+.
> Does it mean we can't scan them (manifest-inputs) out of the builder,
> because they may haven't be realized?

Exactly.

>>> 2. whether we have a gtk+ package in profile
>>
>> That’s no usually the case.  For instance, I have Evince and GIMP in my
>> profile, but not GTK+.
>>
>> What could be done is to check whether GTK+ appears and an direct or
>> indirect dependency of the packages being installed.
>>
>> Currently manifest entries can contain either a package object or a
>> store path.  In the former case, one has to use package->bag and then
>> look for GTK+ in the bag’s transitive inputs.  In the latter, case, one
>> needs to call ‘references’ to check whether the store item, which is
>> already built, depends on GTK+.
>>
>> When none of the manifest’s packages depends on GTK+, then the hook can
>> just return #f, like ghc-package-cache-file does.
>>
>> Does that make sense?
> OK, I'll try this way.
>
> And, which GTK+ we should use to do the icon update?
> How about choose the one referenced by manifest entries
> (either gtk+-2 or gtk+-3) instead of the latest gtk+-3 deployed?

That makes sense.  I guess we’re in trouble if there are both GTK+2 and
GTK+3 packages in use, no?

Thanks,
Ludo’.