these 3 derivations will be built:
  /nix/store/znf3jan5s2xdzigbkhlybrxj39qfmqkn-source.drv
  /nix/store/3wpw52iwnv6d9bb9k3klx89v9gb6hhmj-collie-1.19.2.drv
  /nix/store/0rwj9cbcwibd006q1r48zcir7425q8dr-check-collie.drv