We’ve just merged https://github.com/ManageIQ/manageiq/pull/5982, which bumps us to Rails 5.0.0.beta2.
Unless you’re hanging out for particular new features, this shouldn’t mean much to you – relatively little has changed in the exposed API of existing Rails components (ActiveRecord, ActionController, etc).
Upgrading now gives us the best chance to settle in with the new version, and catch any regressions while there’s still time to get them fixed.
If you run into any issues that seem related, poke me on Gitter and I’ll see what I can do. Other than that, I’ll be working through the deprecations; until I’ve done so, deprecation warnings are temporarily disabled in the test environment, because they’d be a bit overwhelming.