{ config, pkgs, ... }: let unstableTarball = fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz; in { nixpkgs.config = { packageOverrides = pkgs: { unstable = import unstableTarball { config = config.nixpkgs.config; }; }; }; services.syncthing = { enable = true; user = "cyryl"; dataDir = "/home/cyryl/.syncthing"; openDefaultPorts = true; package = pkgs.unstable.syncthing; }; }