these 2 derivations will be built:
  /nix/store/0mccvffkyrghxh6kqn0h6f86644f7v8v-nixos-test-driver-pgtap.drv
  /nix/store/slfj6n5360mpx68y446v6wr8wf6psqp3-vm-test-run-pgtap.drv