these 3 derivations will be built:
  /nix/store/xaxdwr8vqnrbfpvvss8cmp9yi9k64wf5-source.drv
  /nix/store/fcbzxgdpbcws6qvij882ppad0dhd59rr-collie-1.28.1.drv
  /nix/store/8m9i72jczjswijwf33pwd4n8c09lk7ax-check-collie.drv