How to test PHP 8.5 RC1 on Fedora and RHEL systems safely
Remi Collet has released new release candidate packages for the upcoming PHP versions, and testing them before they go live is a smart move for server admins who need stability. This guide explains how to install PHP 8.5 RC1 alongside your current setup without breaking production scripts or system dependencies. The focus here is on using Software Collections to keep things parallel while you run the tests on Fedora or RHEL based distributions.
Why bother testing PHP 8.5 RC1 before the final release?
Developers often wait until a version is stable because bugs in release candidates can disrupt automated build pipelines or crash web applications during peak traffic. Admins have seen this happen after a bad driver update, but it also happens frequently when switching major language runtimes without checking compatibility first. Since PHP 8.3 has moved into security mode only, the team needs to verify that plugins and extensions work correctly with version 8.4 or the newer 8.5 branch before committing to an upgrade. It is better to find a breaking change in a test environment than on a live server during business hours.
Installing PHP 8.5 RC1 as a Software Collection on Fedora or RHEL
Remi has made these packages available through specific testing repositories that allow for parallel installation so existing versions remain untouched. Administrators can enable the remi-test repository and install version 8.5 using yum commands to keep it separate from the system default. The command "yum --enablerepo=remi-test install php85" sets up the new environment in a Software Collection format that does not interfere with standard PHP binaries. This approach is the perfect solution for such tests because it lets you switch contexts without removing the stable version currently handling live traffic.
Managing module switches for system-wide updates later
Once testing confirms stability, users can move to update the system version directly using dnf module commands that handle the transition smoothly. The process involves switching to php:remi-8.5 and then running an update command to pull all related package changes from the remi-modular-test repository. For those sticking with version 8.4, a similar workflow applies by targeting php:remi-8.4 instead of the newer branch. It is important to remember that packages are available for both x86_64 and aarch64 architectures so most modern servers can participate in this testing cycle without hardware limitations.
PHP version 8.4.20RC1 and 8.5.5RC1
Release Candidate versions are available in the testing repository for Fedora and Enterprise Linux (RHEL / CentOS / Alma / Rocky and other clones) to allow more people to test them.
