these 3 derivations will be built:
  /nix/store/9kgf28dqrzbn48gxhar1ky1naa02fjvj-source.drv
  /nix/store/szp7p3ww7l4qcr9qmvm6n8979m1kkjqs-collie-1.23.1.drv
  /nix/store/5cp6jf3lih0gxxig59zq59cdhhzmb1zh-check-collie.drv