these 2 derivations will be built:
  /nix/store/d3zsj7pi6dyzfi1nfz9fii89m090ymy4-nixos-test-driver-pg_cron.drv
  /nix/store/8ai2sd10733xxmhn4apnkc4zxd301ypp-vm-test-run-pg_cron.drv