these 3 derivations will be built:
  /nix/store/fmbnqd2xmpcbkfw3pykyns4skb6ncg58-source.drv
  /nix/store/hi36id3b30lq3x48l7gryya2m4scpd3d-mcptoon-0.8.12.drv
  /nix/store/89zhhqwgks5svmg0z9m4fflv7yzd9vxv-check-mcptoon.drv