Using plugins based on a Ruby runtime

Issue

Some Jenkins plugins are based on the Ruby Runtime, should I use them?

Environment

CloudBees CI (CloudBees Core) on modern cloud platforms - Managed controller
CloudBees CI (CloudBees Core) on traditional platforms - Client controller
CloudBees Jenkins Enterprise - Managed controller
CloudBees Jenkins Platform - Client controller
CloudBees Jenkins Distribution
Jenkins LTS

Resolution

Jenkins is written in Java and most of the plugins are written in Java too. Some plugins are written in Ruby and are depending on the Ruby Runtime Plugin to run. This plugin is providing the Ruby runtime as well as the necessary bindings for plugins written in Ruby to integrate with Jenkins.

There are several issues with this:

the Ruby Runtime Plugin is up for adoption and did not receive any update since 2016.
mixing up Ruby Runtime and Java Runtime is adding complexity and potential bugs.

The recommendation is therefore not to install any plugin depending on Ruby.

How to recognize such a plugin?

Look into the dependencies of the plugin if it depends on the Ruby Runtime Plugin. Note that no Tier 1 or Tier 2 plugin is depending on the Ruby Runtime Plugin.