these 3 derivations will be built:
  /nix/store/wq0bl4zjkmgg8xchxypmyxdy3d29ks5b-source.drv
  /nix/store/iynkbnprsl076pnj55w8d0ydgy4f8piy-herdr-eternal-deps-0.1.0.drv
  /nix/store/yflw5kda4lhpfypq2pbq0ljrhs8q6zyx-herdr-eternal-test-0.1.0.drv