The release notes can be found here: https://github.com/mongodb/mongoid/releases/tag/v6.0.0.rc0
It can be installed from RubyGems using the --pre flag:
gem install mongoid --pre
or explicitly:
gem install mongoid -v 6.0.0.rc0
Please test and report any issues by opening a ticket in our Jira project for Mongoid: https://jira.mongodb.org/browse/MONGOID
Thanks
Emily