these 2 derivations will be built:
  /nix/store/fzl9af5vs5vfabgdkp8dryvi81sad6d0-harmonia-deps-3.1.0.drv
  /nix/store/ljwyss8cdx2wgfbym6k90wmgwqmyglcf-harmonia-llvm-cov-3.1.0.drv