Hi Tobias,

thanks for feedback!

> 
> > (build-dir nix-configuration-build-dir ;string
> > (default "/tmp"))
> 
> 
> ‘directory’. Plz, no unnec. abbrev.
> 
> The concept LGTM. Calling it a ‘build directory’ might be editorialising too much. Does Nix use it for anything else?

I've updated the patch so there is no abbreviation. I asked on Nix matrix channel and was told just for derivations. But I'm not expert so take it with grain of salt.

Ludo',
you have a lot insight into the build infrastructure and you also took the concepts from Nix.

What do you think about this approach? It should not be premanently set to block device as you loose throughput and increase latency, but it's neccessary for some derivations as not everybody can have powerful machine at their disposal.

Is there some way to share the approach with guix daemon? If I remeber correctly the derivation is offloaded to nix backend - the contents of `nix` directory (haven't yet had the chance to go through the C code).

I guess the machines behind 'https://ci.guix.gnu.org' have enough resources. Or is there some script that handles large derivations? 

Also this might be interesting problem for embedded devices though offloading is definitely the best approach.

----
Petr