these 2 derivations will be built:
  /nix/store/f3w8cyzgkxf0d1jpgcbmkzrkx2fl8ryq-iets-0.1.0.drv
  /nix/store/7nd9r54vqa8jf0myf1m30n9k0zqdm5mc-iets-diff-e2e.drv