Magento 2 Controller override not working

Question

I have to override 2 controller 1 override is working and 1 override not working

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="\Magento\Customer\Controller\Account\ForgotPassword" type="\Copper\Customer\Controller\Auth\ForgotPassword" />
    <preference for="\Magento\Customer\Controller\Account\ForgotPasswordPost" type="\Copper\Customer\Controller\Auth\ForgotPasswordPost" />
</config>

While \Magento\Customer\Controller\Account\ForgotPassword override is working just fine. \Magento\Customer\Controller\Account\ForgotPasswordPost is not overriding

Do anyone know Why ?

Controller ForgotPasswordPost.php

<?php
namespace Copper\Customer\Controller\Auth;

class ForgotPasswordPost extends \Magento\Customer\Controller\Account\ForgotPasswordPost
{
    public function execute()
    {
        echo "hello";die();
    }
}

Answer 1

Please remove \ form starting it will be worked

\Magento\Customer\Controller\Account\ForgotPassword it should be like Magento\Customer\Controller\Account\ForgotPassword

Please try this di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="Magento\Customer\Controller\Account\ForgotPassword" type="Copper\Customer\Controller\Auth\ForgotPassword" />
    <preference for="Magento\Customer\Controller\Account\ForgotPasswordPost" type="Copper\Customer\Controller\Auth\ForgotPasswordPost" />
</config>

Answer 2

It's should working fine. There is the only one thing you may have not took into account is put di.xml file in correct area. So di.xml file should be located in app\code\Copper\Customer\etc

And another one thing. If you just want to override method or add new functional before/after to method, please use plugin system it is better way then preference.

http://devdocs.magento.com/guides/v2.2/extension-dev-guide/plugins.html