these 2 derivations will be built:
  /nix/store/vrj4yvdx3w94snn4c1cqy26k8qgi53fw-iets-0.1.0.drv
  /nix/store/7z480nwq3m5l24a5pxsaklhd4crsbah7-iets-diff-e2e.drv