these 3 derivations will be built:
  /nix/store/vqhpmlm7fg98f0vqbmv6nnspnvnkslzb-source.drv
  /nix/store/nbqs9fwdlk3iram34wj42j6cfdz0vqz3-harmonia-deps-3.1.0.drv
  /nix/store/w8vz2vm15hm71ypwwdic6rwz11vm5n85-harmonia-3.1.0.drv