these 2 derivations will be built:
  /nix/store/69zlzxg0qffi8k0a8j83swjhpgyd0mw5-mardi-gras-0.36.0.drv
  /nix/store/kkj8mv3qkrp14wwc65wcx0fxra6qq2wg-check-mardi-gras.drv