R""(
Upgrade Nix to the stable version declared in Nixpkgs:
Upgrade Nix in a specific profile:
This command upgrades Nix to the stable version.
By default, the latest stable version is defined by Nixpkgs, in nix-fallback-paths.nix and updated manually. It may not always be the latest tagged release.
By default, it locates the directory containing the nix
binary in the $PATH
environment variable. If that directory is a Nix profile, it will upgrade the nix
package in that profile to the latest stable binary release.
You cannot use this command to upgrade Nix in the system profile of a NixOS system (that is, if nix
is found in /run/current-system
).
)""