Re: What’s next?

[Ludovic Courtès]

Hi,

Efraim Flashner <efraim@flashner.co.il> skribis:

> On Mon, May 17, 2021 at 10:13:10PM +0200, Ludovic Courtès wrote:
>> Hi,
>> 
>> Efraim Flashner <efraim@flashner.co.il> skribis:
>> 
>> > package-transformations applied to the operating-system field of the
>> > os-config.
>> 
>> Ah, that’s a good one, but possibly tricky!  What would it operate on?
>> Any package?  Only those showing up in the system profile?
>> 
>> The former is not really possible; the latter is.
>> 
>> Ludo’.
>> 
>
> The idea is everything in the system declaration. So the global
> packages, the guix-daemon from the guix-daemon service,

Yeah, that’s not easily possible, in the sense that there’s no place to
“hook” to perform such transforms.  The reason is that references to
packages may be buried down anywhere in gexps or files produced by
services, an obvious example being:

  #~(make-forkexec-constructor
      (list #$(file-append some-package "/bin/xyz")
            …))

The reference to ‘some-package’ here is deep down.

An option would be to have a way to provide ‘lower-object’ a customize
way to lower all the <package> records that it sees, for instance.  But
then, how does that interact with caches, etc.  Tricky!

Ludo’.