these 2 derivations will be built:
  /nix/store/b9zxsflxr2551f4x0lq7zp7fcg0f72qj-nixos-test-driver-postgis.drv
  /nix/store/d3biv3y2wsj8xnf8jm9bg13ngap6pn61-vm-test-run-postgis.drv