Nix store dump-path --recursive not working

Dear all,
I’m trying to save an entire closure of a package to a Nar file or something similar that can be archived and later be imported again. I would assume that nix store dump-path -r $PACKAGE is what I’m looking for, but I can’t get the recursive to work. For example:

$ nix store dump-path -r nixpkgs#nano 
error: this command requires exactly one store path
Try 'nix --help' for more information.

complains about one path being required. Even if I’m explicitly giving that path

$ nix store dump-path -r /nix/store/qjbn8ggqvawhly4rna14bn994g7fyxfq-nano-7.2
error: this command requires exactly one store path
Try 'nix --help' for more information.

it is the same result. Am I misunderstanding the recursive flag or does it simply not work? I’m using Nix 2.18.2.

Best, Phillip