R""(

Note: unlike nix profile install, this command does not take installables.

This command upgrades a previously installed package in a Nix profile, by fetching and evaluating the latest version of the flake from which the package was installed.

Warning

This only works if you used an unlocked flake reference at installation time, e.g. nixpkgs#hello. It does not work if you used a locked flake reference (e.g. github:NixOS/nixpkgs/13d0c311e3ae923a00f734b43fd1d35b47d8943a#hello), since in that case the "latest version" is always the same.

)""