these 2 derivations will be built:
  /nix/store/z5pj7yjfksrknahdk0csrpskfvbl506k-harmonia-deps-3.3.0.drv
  /nix/store/n0bnmqdc66gvd1gg0n4acrndz6qd9in6-harmonia-llvm-cov-3.3.0.drv