these 2 derivations will be built:
  /nix/store/72cs5r1v6h3193hy56ggziadp9vgy7m6-iets-0.1.0.drv
  /nix/store/6gw4r5f1nx656vd7yqkz5hdk8z3jvdm4-iets-diff-e2e.drv