these 2 derivations will be built:
  /nix/store/cbifnp5s9fzc0a85pyzgl7hqgmzw6fkp-iets-0.1.0.drv
  /nix/store/fw4i8wwf1vwrzjfmw6p3hzvscp8yvmdq-iets-partest.drv