these 4 derivations will be built:
  /nix/store/mrmliwagq5xqwcwjrj2qw0i5lmnhznn7-Cargo.toml.drv
  /nix/store/bvbm85m1pij6hyaqkgyx75cvm9gal6y6-source.drv
  /nix/store/1lyg5kipp9n00fl0b2dmj75lrcmj16kr-harmonia-deps-3.2.0.drv
  /nix/store/9fjpzhq3xpp02dc62hhpwq6n1qr1jhlm-harmonia-3.2.0.drv