these 2 derivations will be built:
  /nix/store/ma1bqzqggnazpp96kfrd94dwzamr1q5s-iets-0.1.0.drv
  /nix/store/5fgbp895p4q7ghbdnrlbdz0ayk0bfn2r-iets-diff-e2e.drv