these 4 derivations will be built:
  /nix/store/mkchsxvl2ny05cm5jrwpmlics8xmym8l-Cargo.toml.drv
  /nix/store/nykqgi1jzwwihdnvf6l15k1b8drphm76-source.drv
  /nix/store/nz4s1pvbinnixvwdjm9hna630l15gwjw-harmonia-deps-3.2.0.drv
  /nix/store/4l4xzd0fjxwl4f2h48zmhm4wzbxf0qma-harmonia-3.2.0.drv