these 2 derivations will be built:
  /nix/store/d2nqpp094y62bs1fwjvh8flxi5clzv3x-iets-0.1.0.drv
  /nix/store/y88wgiwms0fgp8ib7gr1k4c0xq7hz8kd-iets-diff-e2e.drv