these 2 derivations will be built:
  /nix/store/5dbrm8dh22d0yirf426l0cwfjdj4qfnr-harmonia-deps-3.2.0.drv
  /nix/store/6nwxghvmffvd50ykp7m1094zshj8ifxi-harmonia-llvm-cov-3.2.0.drv