Why does the autoloader `require` instead of `require_once`? · Issue #11102 · composer/composer · GitHub
![magento2 - Warning: require(vendor/autoload.php): Failed to open stream: No such file or directory in - Magento Stack Exchange magento2 - Warning: require(vendor/autoload.php): Failed to open stream: No such file or directory in - Magento Stack Exchange](https://i.stack.imgur.com/3CxHK.png)
magento2 - Warning: require(vendor/autoload.php): Failed to open stream: No such file or directory in - Magento Stack Exchange
Use require_once instead of require with 'autoload' option. · Issue #867 · composer/composer · GitHub
![require_once __DIR__ . 'sendgrid-php/vendor/autoload.php' not seeing the autoload.php file · Issue #6771 · composer/composer · GitHub require_once __DIR__ . 'sendgrid-php/vendor/autoload.php' not seeing the autoload.php file · Issue #6771 · composer/composer · GitHub](https://user-images.githubusercontent.com/32191704/32134714-090afad4-bbeb-11e7-9355-ae62b830bc01.jpg)