these 2 derivations will be built:
  /nix/store/f9fb1h2mij4bg34b16ry8vwilk7mgd9b-nixos-test-driver-site.drv
  /nix/store/h48clzrb1qhd61ypbzlhazd4zc8hhdnz-vm-test-run-site.drv