warning: Nix search path entry '/nix/var/nix/profiles/per-user/fusion809/channels/nixpkgs' does not exist, ignoring

error: file 'nixpkgs' was not found in the Nix search path (add it using $NIX_PATH or -I), at /data/Programs/targz/nix/runescape-launcher/default.nix:1:17