these 3 derivations will be built:
  /nix/store/59kbhrs7m0yzp8dvnf68ypws594xkksn-source.drv
  /nix/store/0zyj3da5aknmmnk89ncrl6arskvsp3qm-mcptoon-0.8.34.drv
  /nix/store/kr875bb19mhhczg6s5q4nf0a864d07sk-check-mcptoon.drv