Retrieving the singleton class of a class seems to return Class.

[eloy.de.enige@…]

For example:

% cat t.rb
class A
  def self.singleton_class
    (class << self; self; end)
  end
end

p A.singleton_class

% ruby19 t.rb
#<Class:A>

% macruby t.rb
Class

[pthomson@…]

I think the problem here is just in the #inspect method for singleton classes. The object_id's of A's singleton class and A's class are different:

irb(main):008:0> A.singleton_class.object_id
=> 8592372416
irb(main):009:0> A.class.object_id
=> 8590007040
irb(main):010:0> A.class == Class
=> true
irb(main):011:0> A.singleton_class == Class
=> false