these 2 derivations will be built:
  /nix/store/2fhybcf9df8n0vhkjrr7id636hckvm13-nixos-test-driver-plpgsql_check.drv
  /nix/store/c8kmwlbspywry640f0q0aw3q0l1i2hcd-vm-test-run-plpgsql_check.drv