How to remove Deprecated 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.