anchor.diff:  
   let
     inherit (lib) mkIf mkOption singleton types;
  -  inherit (pkgs) coreutils exim;
  +  inherit (pkgs) coreutils;
     cfg = config.services.exim;
   in
   
  
positive.code:       gid = config.ids.gids.exim;
      };
  
      security.wrappers.exim.source = "${exim}/bin/exim";
  
      systemd.services.exim = {
        description = "Exim Mail Daemon";
        wantedBy = [ "multi-user.target" ];
        restartTriggers = [ config.environment.etc."exim.conf".source ];
        serviceConfig = {
          ExecStart   = "${exim}/bin/exim -bdf -q30m";
          ExecReload  = "${coreutils}/bin/kill -HUP $MAINPID";
        };
        preStart = ''
  
negative.code:         '';
        };
  
        package = mkOption {
          type = types.package;
          default = pkgs.exim;
          defaultText = "pkgs.exim";
          description = ''
            The Exim derivation to use.
            This can be used to enable features such as LDAP or PAM support.
          '';
        };
  
      };
  
    };
  