these 2 derivations will be built:
  /nix/store/z1ck2p136v0iq7x76b5wfq3q7pgq9sns-iets-0.1.0.drv
  /nix/store/4dhfchpgqxbdvc6lal1f6d3h1c6kl35b-iets-diff-e2e.drv