these 5 derivations will be built:
  /nix/store/dc0jyd4jf39dk73q81gj9va9nnz6qdsa-Cargo.toml.drv
  /nix/store/n73rf1nzy89khzibqdvvyk5lr1x1w4fq-Cargo.toml.drv
  /nix/store/ikbbhgr5qdw7yzqzlghgp2g31m5g39l4-source.drv
  /nix/store/dc0810pfk37zwkgikb11zch8qg7597dh-harmonia-deps-3.2.0.drv
  /nix/store/cpg8xnq7ygwwhh9xikr0jslyr1ya4y09-harmonia-llvm-cov-3.2.0.drv