By default nix uses a mix of local and remote builds to builds things. To avoid building locally there's a flag --max-jobs 0 so that nix doesn't use your local machine!

Careful though, as if you don't have any remote builders, it just won't work. You can provide the remote builders with your command-line arguments --builders 'ssh://machine'. Note that there are several caveats :

  • if sometimes you do big builds, if the derivation is tagged big-parallel, the builder also needs that. Otherwise it won't get selected.

  • the --builders flag only works on root / Trusted users

    warning: Ignoring the client-specified setting 'builders', because it is a restricted setting and you are not a trusted user

    Which, shouldn't be active for your normal users as IIRC, it's equivalent to docker group, ie, it's a privilege escalation opportunity.

That's it for now!