these 2 derivations will be built:
  /nix/store/6ry7q7cdxzkaph0gd7x4nn8c8f17b6kj-mardi-gras-0.33.0.drv
  /nix/store/lx6dpzkdzz14k84kmyk1a91am5gglp0w-check-mardi-gras.drv