these 2 derivations will be built:
  /nix/store/b88dfw6pl3hzx9ikm2vc63gi9wqq8xif-iets-0.1.0.drv
  /nix/store/8xgf79k4b1wp4d6ilzg7kcdps49lc56h-iets-diff-e2e.drv