these 2 derivations will be built:
  /nix/store/ngs3a1a9ps1kyjdv2bcq0p910jspm5y0-iets-deps-0.1.0.drv
  /nix/store/1gbka3v61wjzbkfzvpm2jkw3ph5cy8xz-iets-doctest-0.1.0.drv