Ruby 2.5 is out and here the release notes.
For more details there is also a news page on github which explains point by point which and how classes, libraries and language got updates.
Now I am waiting spring to fix their issue
Passenger got same issue too
Updating binding_of_caller will fix the spring issueUpdated passenger (5.2.0) will have the fix for their issue too
Time to try 2.5