these 2 derivations will be built:
  /nix/store/b473q23j6lxw3wg34mklv7bw9lpk74qm-nixos-test-driver-pg_net.drv
  /nix/store/hcq8z6rj114xdqgy1l9v4pz3gs3li9z7-vm-test-run-pg_net.drv