Change record status: 
Project: 
Introduced in branch: 
9.0.x
Introduced in version: 
9.0.0
Description: 

Symfony 4 does not include a class loader that implements a wrapping autoloader cached in WinCache. Therefore, Drupal 9 no longer ships with support.

We strongly recommend that if you require a class loader that uses a shared cache you install the APCu extension. It is available on Windows PHP builds.

If a WinCache class loader is required it is possible to use composer to bring back the class loader. To do this you need to:

  1. Use composer to install the Symfony 3 class loader package: composer require symfony/class-loader
  2. Add the following code snippet to settings.php
    if ($settings['hash_salt']) {
      $win_loader = new \Symfony\Component\ClassLoader\WinCacheClassLoader('drupal.' . $settings['hash_salt'], $class_loader);
      $class_loader->unregister();
      $win_loader->register();
      $class_loader = $win_loader;
    }
    
Impacts: 
Module developers
Distribution developers
Updates Done (doc team, etc.)
Online documentation: 
Not done
Theming guide: 
Not done
Module developer documentation: 
Not done
Examples project: 
Not done
Coder Review: 
Not done
Coder Upgrade: 
Not done
Other: 
Other updates done