Laravel 查询拼接问题

$condition = $request->all();
 $perm_list = Permission::select('*');
if ($request->has('pname')) {
    $perm_list->where('name','like','%'.$request->get('pname').'%');
}
$perm_list->paginate(2);

这样的一个查询，就是如果有pname，条件增加pname，如果没有，就全部，输入结果分页
但是报错

ErrorException in Builder.php line 2405:
Call to undefined method Illuminate\Database\Query\Builder::appends() (View: /vagrant/manage/resources/views/acl/permission.blade.php)

请教高手!