these 4 derivations will be built:
  /nix/store/ck5dfnyqaw2nxq05f1vrai6m12s2z1wq-Cargo.toml.drv
  /nix/store/5fwn9jhqdvhypakzk3s8q6avf5w77l0s-source.drv
  /nix/store/gx33nnwpw89kvnbpmcy1431i77cs6r6a-iets-deps-0.1.0.drv
  /nix/store/q8g7qxfyrys7lvig5mirlsvqgqhvgr69-iets-nextest-0.1.0.drv