these 3 derivations will be built:
  /nix/store/ck6m5ibisk880nz3xml8h8w3ghp9c044-source.drv
  /nix/store/qh9992p57j61yqzbi2ra6f7pwn12w4nh-mcptoon-0.8.21.drv
  /nix/store/7bb4m7bpnczjcb9m1rk536jxkq3qyy7i-check-mcptoon.drv