6fa690291a
This command upgrades Nix to the latest stable version by installing a store path obtained from https://github.com/NixOS/nixpkgs/raw/master/nixos/modules/installer/tools/nix-fallback-paths.nix which is the same store path that the installer at https://nixos.org/nix/install.sh uses. The upgrade fails if Nix is not installed in a profile (e.g. on NixOS, or when installed outside of the Nix store).