module Builders

  class NoBuildersRegisteredError < StandardError
  end

  class Registry

    class << self

      def registered_builders
        if @registered_builders.blank?
          Builders::Registry.register(Builders::TestRail) unless Chamber.env.test_rail.nil?
          Builders::Registry.register(Builders::ManualBuilder)
        end
        @registered_builders.values unless @registered_builders.blank?
      end

      def register(builder)
        @registered_builders = {} if @registered_builders.blank?
        @registered_builders[builder.builder_name] = builder
      end

      def find_by_builder_name(name)
        raise NoBuildersRegisteredError if registered_builders.blank?
        @registered_builders[name]
      end
    end
  end
end

module Builders

  class NoBuildersRegisteredError < StandardError
  end

  class Registry

    class << self

      def registered_builders
        if @registered_builders.blank?
          Builders::Registry.register(Builders::TestRail) if Chamber.env.test_rail?
          Builders::Registry.register(Builders::ManualBuilder)
        end
        @registered_builders.values unless @registered_builders.blank?
      end

      def register(builder)
        @registered_builders = {} if @registered_builders.blank?
        @registered_builders[builder.builder_name] = builder
      end

      def find_by_builder_name(name)
        raise NoBuildersRegisteredError if registered_builders.blank?
        @registered_builders[name]
      end
    end
  end
end

Change to use Chamber method
Change to use Chamber method
