these 3 derivations will be built:
  /nix/store/bl55dmlg8f48cki2n8hnmkyksl43bqbq-source.drv
  /nix/store/33698rwbsb82g8x9pwcqsmpb6ci15bak-collie-1.27.1.drv
  /nix/store/hd52y8wf3x4xy0yzkmgzw44ph6ihs18m-check-collie.drv