these 2 derivations will be built:
  /nix/store/04bppbaj0rhrjjfiiv5l9vbr4cfkyg1l-iets-0.1.0.drv
  /nix/store/vbfmfx4dfaikia7pm35cp1jzf3jvfp4i-iets-diff-e2e.drv