First, I need to rectify something I wrote in the previous post: no, PECL is not dead! I misunderstood the situation like the people in charge of the Docker’s image did, you can see it here: https://github.com/docker-library/php/pull/1088 . This is a relief as it’s not necessary anymore to move from PECL to Pickle.
And now that I’ve got a PHP 8 stack up and running with Symfony 5.2, I can share it online so everyone can clone (or just read) it: https://github.com/alexdebril/php8-stack
It’s worth saying that this stack comes with a level of performance I never had before with a fully-configured framework.