these 2 derivations will be built:
  /nix/store/10fg2j6d756y3y559pxw1fvq61kv5b7g-iets-0.1.0.drv
  /nix/store/kc11cchq2qg2csvr8bxmrn5cf1x5xmmr-iets-diff-e2e.drv