these 5 derivations will be built:
  /nix/store/ah5hrz8k8427n4fcksdd83im4674vxz5-Cargo.toml.drv
  /nix/store/qva7xsfcqrh9aazaw4x7zvsrff4z1xim-Cargo.toml.drv
  /nix/store/mr0r9pigi0hrq6hqyi705v3dxkgxhn3x-source.drv
  /nix/store/bays9xgvz5y7yqyvq7v6ys3yavq3sdyc-harmonia-deps-3.2.0.drv
  /nix/store/5gswlfairhbylfl7pyikchv2kznfjqz2-harmonia-llvm-cov-3.2.0.drv