Versions of Ruby that Event machine supports

[Anubhav Kapoor]

Hi I am trying to run my RoR application by using command "rails server".

It gives an error Unable to load the EventMachine C extension; To use the pure-ruby reactor, require 'em/pure_ruby'

I want to ask whether eventmachine supports ruby 2.4.2??

Also then if eventmachine is not supported for 2.4.2 then how the applications are built on it?