these 3 derivations will be built:
  /nix/store/q93c1ihf7fwva0fx4chk0va73lm9aqrq-source.drv
  /nix/store/6ap2rkgrjpzr8x7vbh01mp39hhy4ppn9-collie-1.24.3.drv
  /nix/store/3k1mpvi71l4cgyc27bkv82aa9vjqmv8g-check-collie.drv