these 2 derivations will be built:
  /nix/store/w621bxk4ycxqaaz75gjilb2djsz3p86l-nixos-test-driver-pg_jsonschema.drv
  /nix/store/cvgv1xgak0gdz6vmndrjccn529rjw10x-vm-test-run-pg_jsonschema.drv