these 3 derivations will be built:
  /nix/store/inj7shb6awfb71mmymqa15p76xg1gyff-source.drv
  /nix/store/qdzkh0gb6vc38pmq4891pnspgh1gwvyx-collie-1.25.5.drv
  /nix/store/8lgihj2jwjbcb4vaha93y8qzv91csc66-check-collie.drv