Magento 2.2.2: Customer Grid Indexer not working

Question

While re indexing got an error:

PHP Fatal error: Uncaught Error: Call to undefined method Magento\Customer\Model\Indexer\Source::addAttributeToSelect() in /var/www/html/ncsmokehouse/vendor/magento/framework/Indexer/Handler/AttributeHandler.php:38

Answer 1

Add a function :

public function addAttributeToSelect($fieldName, $alias = null)
    {
       $this->customerCollection->addAttributeToSelect($fieldName, $alias);
       return $this;
   }

in this file /www/vendor/magento/module-customer/Model/Indexer/Source.php

you can override this file because we can't change in core module. it's working

Answer 2

In my case, it works. However, after that, I've found another reindex issue, which I've solved by following this Magento 2 How to Unlock Reindex Process: Index is locked by another reindex process Skipping