these 4 derivations will be built:
  /nix/store/a2ifiirjm2yv9mgmfngxsawp36kkchpp-Cargo.toml.drv
  /nix/store/jzmn7vfd59n9ilnrp9hmdkk2797v41r5-source.drv
  /nix/store/pirxzxmwblnzhp1m48xn2walymb0pf9v-harmonia-deps-3.2.0.drv
  /nix/store/v46p0fw52rkjzfkfbyhbs8jfr6s4imzl-harmonia-3.2.0.drv