How to fix a bug in the rails gem (breadcrumbs on rails)?

Question

Ruby on Rails

I do everything according to the instructions exactly like the author of the gem: https://github.com/weppos/breadcrumbs_on_rails I have already started creating a controller like his with the same name. All in all it gives me this error:

undefined method `add_breadcrumb' for MyController:Class

How to fix? ruby version: ruby ​​2.1.8p440 (2015-12-16 revision 53160) [x86_64-linux]
rail version: Rails 4.2.5.1
--------------
In general, I do the following:
in Gemfile > > open controller My write there
gem "breadcrumbs_on_rails"
bundle install

class MyController

  add_breadcrumb "home", :root_path
  add_breadcrumb "my", :my_path

  def index
     add_breadcrumb "index", index_path
  end

end

into the layouts/ application.rb view I insert into the body
<%= render_breadcrumbs :separator => ' / ' %> I
tried to insert it into show.html.erb and still gives

undefined method `add_breadcrumb' for MyController:Class

Answer 1

The easiest way to fix a gem is to write a monkey patch for the gem method. And immediately on the github to fix it in the near future. Until then, use the monkey patch.