these 4 derivations will be built:
  /nix/store/0xwwc6bpi3rcw9wgggahmc1pf16vaa0z-nix-tarmac-0.1.0.drv
  /nix/store/3lymx0l2l5d7ydjbsvrnblj8x8pyv350-nix-tarmac-0.1.0.drv
  /nix/store/qv4k7a72qbh3c0sh943v76jr1z6zjfza-nix-tarmac-0.1.0.drv
  /nix/store/dgcsjzz15lva4qkd754kirxzrs8vsyq6-nix-tarmac-dispatcher.drv