Just set nix.distributedBuilds to true and nix.buildMachines
to a list of machines that can perform Nix builds via SSH,
and local builds will be forwarded appropriately. So now
any user can say something like
nix-build /etc/nixos/nixpkgs/ --arg system '"powerpc-linux"' -A libxml2
and the build for powerpc-linux will be forwarded to a machine
of that type.
svn path=/nixos/trunk/; revision=9696