Recommend only byebug for ruby 2.X
Recommend only byebug for ruby 2.X

debugger2's author recommends byebug, so let's not force users to research about this and, at the same time, prevent them from mistakenly choosing debugger2 because of the great popularity and skills of its author.
cldwalker/debugger,cldwalker/debugger,cldwalker/debugger