these 2 derivations will be built:
  /nix/store/mmwln6i1xv2p1q2mi4gbgsghw95g61w3-nixos-test-driver-plpgsql_check.drv
  /nix/store/cj6qx50gljf6v2sgw9mpym8pn87v7n46-vm-test-run-plpgsql_check.drv