these 4 derivations will be built:
  /nix/store/rk49zyv9s54p9p2hf5rhp5da5pwcmq8h-Cargo.toml.drv
  /nix/store/spj1az5vm2rlsd821xy63yv80in07pfv-source.drv
  /nix/store/mp4n4a8ip62g01yjpr820k4i6cbzjfmw-harmonia-deps-3.2.0.drv
  /nix/store/i7lnca98kxsrb5cgv94gibvbmcsd51b0-harmonia-3.2.0.drv