these 2 derivations will be built:
  /nix/store/h8d6mg8lwl7bw28yzq24l2g46lnca8s9-iets-0.1.0.drv
  /nix/store/3jpw4xj5aigga4fyv3rj7rjmrmzshal5-iets-diff-e2e.drv