these 3 derivations will be built:
  /nix/store/7m03yhvz3693y02bsvfgj5idnizq9bgy-source.drv
  /nix/store/n4x0c3xbqjd6wgfmwnvi3kgwk0fijngc-mcptoon-0.8.22.drv
  /nix/store/h0955wj0y20bc8za1mrmybrwlrd8jhfa-check-mcptoon.drv