these 2 derivations will be built:
  /nix/store/2n8yfg76d0n6bp24db6phlkxgphys39f-iets-0.1.0.drv
  /nix/store/pd1hv1ffwcmnc8vhi5ygd0zm7nfhd3l7-iets-diff-e2e.drv