these 2 derivations will be built:
  /nix/store/jr4db4q9qb8vgfhxjn3wfwpwlqcg9ckm-flake-inputs.drv
  /nix/store/3jfj1r8y4wk5fwxyf7islfkivlr4xbcp-check-flake-inputs.drv