these 3 derivations will be built:
  /nix/store/2mvi8fbfyqpjwxaq4w8qbpjvw8gxgids-source.drv
  /nix/store/41x4zw9dcawyfrs0kw5b4ri1f36zdfwy-herdr-eternal-deps-0.1.0.drv
  /nix/store/d1ppckpyijp1mjdw47j3a71h9lzaigam-herdr-eternal-test-0.1.0.drv