these 2 derivations will be built:
  /nix/store/k0rgkrcyf13894z3c7lyb9n72krxajqm-mardi-gras-0.34.0.drv
  /nix/store/wq8r5g7xdqb49kngsq3ndhw431dpx76z-check-mardi-gras.drv