these 3 derivations will be built:
  /nix/store/fhkh79lv53y3gsczbwya0h5ppxcvy9a4-nixos-vm.drv
  /nix/store/ykdiqrg8v7lb0z00v3bb4xmzwy58hgc6-nixos-test-driver-plpgsql_check.drv
  /nix/store/3c4kdr28i6vwavvih0597hm9ivq0kxl3-vm-test-run-plpgsql_check.drv