middleman/middleman-core/lib/middleman-core/core_extensions/show_exceptions.rb

# Require lib
require 'rack/showexceptions'

# Support rack/showexceptions during development
module Middleman
  module CoreExtensions
    module ShowExceptions
  
      # Setup extension
      class << self
    
        # Once registered
        def registered(app)
          # When in dev
          app.configure :development do
            # Include middlemare
            if show_exceptions
              use ::Middleman::CoreExtensions::ShowExceptions::Middleware
            end
          end
        end
      end
  
      # Custom exception class
      # TODO: Style this ourselves
      class Middleware < ::Rack::ShowExceptions
      end
      
    end
  end
end