const_weird.rb

module Consts
  Val = 3
end

module Mod
  class Foo
    include Consts

    module Bar
      def baz
        p Module.nesting
        p ::Mod::Foo::Val
        p Val
      end
    end
  end
end

class Mod::Foo
  include Bar
end

puts Mod::Foo.new.baz