I use pry-byebug and no matter when I use the command `show-stack`, it's always empty. When I try to do `up`, I have always "Nowhere to go!". This is the gem list : ``` $ gem list | grep pry pry (0.10.1) pry-byebug (2.0.0) pry-rails (0.3.2) pry-stack_explorer (0.4.9.1) ```