these 2 derivations will be built:
  /nix/store/yvrmyz2dz9gk4jbqbqhxn665hcic5fxy-iets-0.2.0.drv
  /nix/store/wabj0gld0qiwwi5a8xhskkpgjsasvfvq-iets-classic-2.34.9.drv