Re: hydra.gnu.org now provides substitutes for ‘guix pull’

[Ludovic Courtès]

Hi,

address@hidden skribis:

> On June 22, 2018 9:32:58 AM GMT+02:00, address@hidden wrote: 
>
>> Hello Guix,
>> 
>> Yesterday Clément and I discussed on IRC what it would take for Hydra to
>> build build-aux/hydra/guix-modular.scm (i.e., the derivations that
>> correspond to 'guix pull'.)  Clément rightly suggested that it was a
>> matter of removing '--fresh-auto-compiled' from hydra-eval-guile-jobs¹,
>> which I did, and it works:
>> 
>> https://hydra.gnu.org/jobset/guix/modular/
>
> Fantastic!
> This really drastically cut the time to pull for me. Now the only thing
> that takes a toll is to compute the guix-derivation. Can we
> skip/workaround that too? Maybe we can deduce this from the build hydra
> already did?

No, it cannot be deduced.  Essentially this slow part is about finding
out what needs to be built from scratch, IOW, bootstrapping.  See
<https://debbugs.gnu.org/cgi/bugreport.cgi?bug=27284#133> for more info.

We can probably optimize it, but I’m not sure how.

Ludo’.