Re:Gitlab 11.10 Released
by smcg-gitlab on Friday April 26, 2019 @10:44AM
(#19758045)
https://blog-rails5-upgrade.about-src.gitlab.com/2019/04/10/... is a WIP blog post about how we upgraded to Rails 5 which might be interesting, too.
There is no plan to ship with unstable/master that I know of.