these 3 derivations will be built:
  /nix/store/gxwil8raqq3pw4lyb24cp61cgdwyjbl4-source.drv
  /nix/store/0l3vh21sp4hypzigya93zc6agqyrzlmq-collie-1.27.0.drv
  /nix/store/simigkrpa45474q9fpi2xxwipnlvlrfx-check-collie.drv