these 2 derivations will be built:
  /nix/store/v1jxgr7zsxwil9a9pdqhdb3h3g2prn54-iets-0.1.0.drv
  /nix/store/9l1lr82ry30hfwypz7sdy59cz4q1j2fm-iets-diff-e2e.drv