Typo:
Would it be possible to have nested anonymous classes be loaded at *preload* time?

Can you please share the relevant code in Symfony?

The first affect class is this one:
https://github.com/symfony/symfony/blob/7c90c8ba84f24e3d4b62c02eeb8b14ce23eff59f/src/Symfony/Component/HttpKernel/Kernel.php#L459

> $cache = new class($cachePath, $this->debug) extends ConfigCache {

Right now, this anonymous class cannot be linked during preloading because the ConfigCache is not available. Then, at runtime, when the code path is hit, the error occurs.

I wish there would be a way to discover programmatically that the ConfigCache class is required so that it could be loaded.
Apparently, there is one internally, since opcache is able to trigger this warning:
> Can't preload unlinked class class@anonymous: Unknown parent Symfony\Component\Config\ConfigCache

But that's too late for me to do anything about it.
Of course, I could explicitly list ConfigCache for preloading - but this doesn't work in the generic case as it requires ad-hoc knowledge of the codebase.

Of course, using regular class autoloading would work also instead of the current error.

Maybe all missing symbols could trigger the autoloader before linking happens?

This ended up getting fixed by https://github.com/php/php-src/pull/5260.

I still have this error with the symfony bundle omines/datatables-bundle.

> Uncaught PHP Exception Symfony\Component\ErrorHandler\Error\FatalError: "Error: Anonymous class wasn't preloaded" at /var/www/app/vendor/omines/datatables-bundle/src/Adapter/Doctrine/ORMAdapter.php line 329

It's here: https://github.com/omines/datatables-bundle/blob/5ccdc1283ff1931c8259796447b8e69f48ea5302/src/Adapter/Doctrine/ORMAdapter.php#L329

I'm using PHP 7.4.13