these 2 derivations will be built:
  /nix/store/qkdwmliz0j0p693rf1f1nqbxn1s8q5r1-iets-0.2.0.drv
  /nix/store/ayhfm17w4vlghs448lfick40rz5wki1i-iets-classic-2.34.9.drv