these 2 derivations will be built:
  /nix/store/a3abqczfv24pzcpk4cbj253yvya52dvd-iets-0.2.0.drv
  /nix/store/fypm4nk5lf43y9xgz7gfljhfrxsiypn0-iets-classic-2.34.9.drv