these 2 derivations will be built:
  /nix/store/819260rn8nh9gqdgdgkavgxvj1wyx98k-nixos-test-driver-pg_jsonschema.drv
  /nix/store/bzr2yk9zgmvjcymkahvxihx4a4d2ga0d-vm-test-run-pg_jsonschema.drv