these 2 derivations will be built:
  /nix/store/fbwfn7qynpf83gpc7hhwxnqwsixd5sdr-harmonia-deps-3.3.0.drv
  /nix/store/1nqiwq0ngjrh2x6p9cagmb30ghqgvi44-harmonia-llvm-cov-3.3.0.drv