When upgrading to JRuby 9.2.4 our ./dev-setup script no longer competes because of a failure to find libyaml. After running the dev-setup script with an older JRuby and attempting to run our tests with 9.2.4 we have many failures failing to load a JRuby container with Puppet (usually indicative of something causing Puppet to stacktrace).
When running Puppet's benchmarks with JRuby 9.2.4 installed with ruby-install it fails to find the environment to run in and cannot run.
These issues affect JRuby 9.2.1 - 9.2.4.
There's a number of bizarre version conflicts as well when install 9.2.4. I've resolved them using all of the latest versions of libraries.