these 2 derivations will be built:
  /nix/store/y4qjb3i6kr1knqh9zpd68ai9f8qq02ll-nixos-test-driver-pgtap.drv
  /nix/store/mgq7mfp76ixp8vylryw4p949mgl8cznq-vm-test-run-pgtap.drv