these 2 derivations will be built:
  /nix/store/j7pkmf2znf65qynpglj3sf1g5mv0ji4h-iets-0.1.0.drv
  /nix/store/y3j4vcf8mp4h6nj8sdh5xpvp8yflx0cz-iets-diff-e2e.drv