these 2 derivations will be built:
  /nix/store/ic1nd9s7l0fhiw0xn5c983njjyp39n4g-iets-0.2.0.drv
  /nix/store/ciai6lpxp9lm3g9rzds9lhdg77lmk0yj-iets-classic-2.34.9.drv