these 2 derivations will be built:
  /nix/store/ai9zsb6zrh07qy1jqs47p9gz2d6n8cgq-iets-0.2.0.drv
  /nix/store/5h48llxn1j5vnhrsgszb9nllm5vqp5xy-iets-classic-2.34.9.drv