these 2 derivations will be built:
  /nix/store/nb6ckjlh4cdx6yl1v7rmhkx2xx1qx6p0-iets-0.1.0.drv
  /nix/store/rmz6fhsxid29cqfrlymgdjfrklyrrqjn-iets-diff-e2e.drv