No, this is not a real Sinatra error :).
This is the personal homepage of Elad Meidar, a web developer and an entrepreneur specializing in Ruby on Rails. I hang around in Israel, and i am currently having the best time of my life over at Fiverr.com
I am a proud member of RailsBridge, Helping new Rails developers get into our world and also contributed a few Patches to the Ruby on Rails core.
We all know the good old
rake db:migrate:up VERSION=migration_timestamp # Runs the self.up
rake db:migrate:down VERSION=migration_timestamp # Runs the self.down
You're seeing this error because I think it is funny.