these 3 derivations will be built:
  /nix/store/ag5ca48mx1fpxqrsdfh73nygr0rfr1sl-source.drv
  /nix/store/cg67xwpm7laxrli9qcr0wlhkd3vpchk2-mcptoon-0.8.32.drv
  /nix/store/l5cfjznpx1jb9x51xpf9gmdc06g3s524-check-mcptoon.drv