Documentation :

emblem-notice-24.pngThis new major version requires PHP ≥ 7.0 and is not backward compatible with previous version, so the package is designed to be installed beside version 5.

Installation, Fedora:

dnf --enablerepo=remi install phpunit6

Installation, Enterprise Linux:

yum --enablerepo=remi install phpunit6 php-phpunit-dbunit3

A forward compatibility feature have been implemented in version 4.8.35 and 5.7 which allow to use the new namespaces, adaptation is quite simple (examples: fedora/autoloader, GLPI or tc-lib-color).

Notice: this tool is an essential component of PHP QA in Fedora. I quickly plan an Also available for update in Fedora 26.