如何删除弃用的 Symfony\Component\Debug\DebugClassLoader？

Question

I have upgrade Symfony 3.4 to 4.4. The only Deprecation warning left is this:

php.INFO: User Deprecated: The "Symfony\Component\Debug\DebugClassLoader" class is deprecated since Symfony 4.4, use "Symfony\Component\ErrorHandler\DebugClassLoader" instead. {"exception":"[object] (ErrorException(code: 0): User Deprecated: The "Symfony\Component\Debug\DebugClassLoader" class is deprecated since Symfony 4.4, use "Symfony\Component\ErrorHandler\DebugClassLoader" instead. at /vendor/symfony/symfony/src/Symfony/Component/Debug/DebugClassLoader.php:16)"} []

I am not use DebugClassLoader anywhere. How do I remove this warning?

Answer 1

Check your index.php and your bin/console files.

In index.php , for example, there should be a part like this:

if ($_SERVER['APP_DEBUG']) {
    umask(0000);

    Debug::enable();
}

But the corresponding import is likely to be:

use Symfony\Component\Debug\Debug;

In both files change it to:

use Symfony\Component\ErrorHandler\Debug;

Answer 2

Check your bin/console file.

You need change:

use Symfony\\Component\\Debug\\Debug;

to:

use Symfony\\Component\\ErrorHandler\\Debug;

When command is executed you will receive a deprecation message.

Answer 3

in Configuration.php (vendor/codeception/codeception/src/Codeception)

set

'convert_deprecations_to_exceptions' => true

That worked good for me

Answer 4

If you check the trace, you will see:

User Deprecated: The "Symfony\Component\Debug\DebugClassLoader" class is deprecated since Symfony 4.4, use "Symfony\Component\ErrorHandler\DebugClassLoader" instead.
Show context    Hide trace
{▼
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/Debug/DebugClassLoader.php:16 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/VarDumper/Caster/ExceptionCaster.php:216 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/VarDumper/Caster/ExceptionCaster.php:149 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php:341 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/VarDumper/Cloner/VarCloner.php:209 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/VarDumper/Cloner/AbstractCloner.php:274 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DataCollector/DataCollector.php:85 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/DataCollector/LoggerDataCollector.php:75 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Profiler/Profiler.php:100 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/EventListener/ProfilerListener.php:127 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/WrappedListener.php:126 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php:264 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php:239 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/EventDispatcher.php:73 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/EventDispatcher/Debug/TraceableEventDispatcher.php:168 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/HttpKernel.php:103 {▶}
  /var/www/html/vendor/symfony/symfony/src/Symfony/Component/HttpKernel/Kernel.php:166 {▶}
  /var/www/html/web/app_dev.php:13 {▼
    › $response->send();
    › $kernel->terminate($request, $response);
    › 
  }
}

It seems to be coming from Symfony/Component/HttpKernel/Kernel .

Search the usage in vendor folder, if it comes from other component than Symfony, check maybe newer version of the component, has a fix for it. If the deprecated component is used by only Symfony itself, I would not spend too much time worrying about it. It will get resolved, once you upgrade your Symfony to the next major version.