these 2 derivations will be built:
  /nix/store/z6mqa0j81q9w897v6z81ywghd6gi0q1y-nixos-test-driver-pgtap.drv
  /nix/store/zizz2zpgynhn2jvzc0kn5in5smp41zfp-vm-test-run-pgtap.drv