On Wed, 9 Aug 2017, Ricardo Wurmus wrote:

> Before a substitute can be requested, Guix will have to compute a
> derivation locally.  In the case of Guix itself this is rather
> expensive.
>
> Once we have the derivation we can ask substitute servers if they have a
> binary substitute for performing the work the derivation describes.
>
> So, local *computation* cannot be avoided, but local building should be
> avoidable for most packages — here the problem is that hydra isn’t fast
> enough yet.  I’ve been preparing an alternative build farm at the
> institute where I work, which will hopefully soon be powerful enough to
> build packages more quickly than our current Hydra does.

Thanks!!