anchor.diff:    config = mkIf cfg.enable {
       home.packages = [ pkgs.direnv ];
   
  +    xdg.configFile."direnv/config.toml" = mkIf (cfg.config != {}) {
  +      source = configFile cfg.config;
  +    };
  +
       xdg.configFile."direnv/direnvrc" = mkIf (cfg.stdlib != "") {
         text = cfg.stdlib;
       };
  
positive.code:   options.programs.direnv = {
      enable = mkEnableOption "direnv, the environment switcher";
  
      stdlib = mkOption {
        type = types.lines;
        default = "";
        description = ''
          Custom stdlib written to <filename>~/.config/direnv/direnvrc</filename>.
        '';
      };
  
  
negative.code: let
  
    cfg = config.programs.direnv;
    configFile = config:
      pkgs.runCommand "config.toml" { buildInputs = [ pkgs.remarshal ]; } ''
        remarshal -if json -of toml \
          < ${pkgs.writeText "config.json" (builtins.toJSON config)} \
          > $out
      '';
  
  in
  
  