these 3 derivations will be built:
  /nix/store/phwpvd95q4lmcvydvp85nqnayx56hxcg-source.drv
  /nix/store/940sdw4n7vqgw6jrf0yqgp4yjrf90jpv-collie-1.25.4.drv
  /nix/store/mmd1pxgbmmpcjv52nhszakyrxqznskkn-check-collie.drv