these 3 derivations will be built:
  /nix/store/8k9ghrqclj1qbgmnp2vy9wwkvzg03n0x-source.drv
  /nix/store/hn9zhxfv2lgf1rf7w0cpcxfy463896gw-harmonia-deps-3.2.0.drv
  /nix/store/1gd3f5j85530zpqj3bmqmprf7q9whsy0-harmonia-llvm-cov-3.2.0.drv