PHP 7.2 no Fedora 27

Vamos utilizar o repositório do Remi:

wget http://rpms.remirepo.net/fedora/remi-release-27.rpm

Instale:

sudo dnf install remi-release-27.rpm -y

Instale o dnf-plugin:

sudo dnf install dnf-plugins-core -y

Ative o repositório:

sudo dnf config-manager --set-enabled remi-php72

E instale o php:

sudo dnf install php -y

Feito!

php -v
PHP 7.2.2 (cli) (built: Jan 30 2018 10:33:36) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

Guia de referência: https://blog.remirepo.net/