these 2 derivations will be built:
  /nix/store/i5a6xwv9ff6sz1jb3r4x3y2avv28qn0v-nixos-test-driver-pgtap.drv
  /nix/store/xbhh6z4xrg5i36dh3vwjkpxzfv933avd-vm-test-run-pgtap.drv