Re: Medium-term road map

[zimoun <zimon.toutoune@gmail.com>]

Dear,

On Sun, 3 May 2020 at 22:07, Ludovic Courtès <ludo@gnu.org> wrote:

> We could write a program to build a database locally (I very much like
> the idea of “substitutes” viewed as an optimization compared to local
> computation) but that would be expensive, although it could be
> incremental.

I agree that the "substitutes" mechanism seems the right approach.
Because it allow the user to build the something locally (if they do
not trust the server or use Guix for another set packages etc.).

However, the "issue" with substitutes when pulling is that they are
rarely available.  Because Guix moves faster than the build-farm
builds; I mean my laptop is building locally -- more more than often
-- guix-manual, guix-cli, guix-extra, guix-cli-modules,
guix-extra-modules, guix-packages-base, etc. and some expensive ones ,
e.g., guix-system.


> I suppose we could reuse relevant bits of the Data Service as a library.
>
> Hmm thinking about it, by building the package-cache derivation of each
> Guix revision, one already gets a lot of information, and that is
> substitutable.  Food for thought!

Yes.  What I have in mind is: substitute a big index once and then
update it locally (incrementally, similarly as 'news' does).
The questions are:
  what does that? pull or explicit command or something else?
  how to deal with channels?


All the best,
simon