Ho cancellato la cartella symfony e rifatto installazione da capo.
Settando il selinux a disabled la pagina config.php non mi da errori
la pagine app_dev.php

Fatal error: Uncaught exception 'RuntimeException' with message 'Unable to create the cache directory (/var/www/html/symfony/app/cache/prod) ' in /var/www/html/symfony/app/bootstrap.php.cache:2602 Stack trace: #0 /var/www/html/symfony/app/bootstrap.php.cache(2563): Symfony\Component\HttpKernel\Kernel->buildContainer() #1 /var/www/html/symfony/app/bootstrap.php.cache(2343): Symfony\Component\HttpKernel\Kernel->initializeContainer() #2 /var/www/html/symfony/app/bootstrap.php.cache(2374): Symfony\Component\HttpKernel\Kernel->boot() #3 /var/www/html/symfony/web/app.php(28): Symfony\Component\HttpKernel\Kernel->handle(Object(Symfony\Component\HttpFoundation\Re quest)) #4 {main} thrown in /var/www/html/symfony/app/bootstrap.php.cache on line 2602

Se provo poi a lanciare un chmod -R 777 cartella_progetto/ e provo ad accedere a app_dev.php

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