these 3 derivations will be built:
  /nix/store/3vxn9llgyqd8fcqshkasnaglb4aasqka-source.drv
  /nix/store/6xnskl14mzyb12zgdsd07zrssmql384f-collie-1.12.1.drv
  /nix/store/6sjb32xh4msmbfcyyyqw16zfqlpnpvab-check-collie.drv