First of all: I dont know ruby (yet) as I will start from the front end.
this code was produced by this plugin generator. so its not my fault. Its the generators fault. I typed nothing while following the tutorial. I just followed the development environment setup guide for ubuntu. Before running the generator the local discourse instance worked fine.
https://github.com/discourse/discourse/blob/master/lib/generators/plugin/templates/plugin.rb.erb
to be very clear: I am just at the first page of this tutorial. specifically the part that links to this plugin generator.