使用 entrust 报错 Creating default object from empty value

  public function setupBillAndDomainRolsPermission()
    {
        // Create Roles
        $Bill = new Role;
        $Bill->name = 'BillAdmin';
        $Bill->save();
        $Domain = new Role;
        $Domain->name = 'DomainAdmin';
        $Domain->save();
        // Create User
        $user = new User;
        $user->name = 'jobs888';
        $user->password = 'Zzzzzq795283';
        if(! $user->save()) {
            Log::info('Unable to create user '.$user->username, (array)$user->errors());
        } else {
            Log::info('Created user "'.$user->username.'" <'.$user->email.'>');
        }
        // Attach Roles to user
        $user->roles()->attach( $Bill->id );
        // Create Permissions
        $manageDomain = new Permission;
        $mangeeDomain->name = 'manage_domain'; // 106行
        $mangeeDomain->display_name = 'DomainManager';
        $manageDomain->description = 'Manage Domain';
        $mangeeDomain->save();
        $manageBill = new Permission;
        $manageBill->name = 'manage_bill';
        $manageBill->display_name = 'BillManager';
        $manageBill->description = 'Manage Bill';
        $manageBill->save();
        // Assign Permission to Role
        $Bill->attachPermission($manageBill);
        $Domain->attachPermission($manageDomain);
    }

 报错如下: local.ERROR: exception 'ErrorException' with message 'Creating default object from empty value' in E:\vmdisk\database\migrations\2015_08_16_040510_entrust_setup_tables.php:106Copy