these 3 derivations will be built:
  /nix/store/rlpbnq2rfm8xi126v88c1hhsblxc00k7-source.drv
  /nix/store/4llfnv3jcf2i0yl6yspls1gh11nh4j2q-collie-1.16.1.drv
  /nix/store/42si4fd42lxyri144789pl4vxapmxnmf-check-collie.drv