Why won't symfony/demo install?

Question

symfony

I install according to the manual symfony/demo .
Requirements

Install PHP 7.2.5 or higher and these PHP extensions (which are installed and enabled by default in most PHP 7 installations): Ctype, iconv, JSON, PCRE, Session, SimpleXML, and Tokenizer;
Install Composer, which is used to install PHP packages.

Correspond: it costs php8, all extensions are there, the composer is the latest version.

symfony new . --demo

gives this game:




At the same time, symfony/website-skeleton is installed normally.

Answer 1

The problem is in php8. Officially, only php 7.4 branches are supported so far.