以下がコケてしまうのはバグでしょうか?

  $ ruby -v -rsocket -rmutex_m -e 's=TCPSocket.new("localhost",25); s.extend(Mutex_m)'
  ruby 1.6.4 (2001-06-04) [i386-linux]
  /usr/lib/ruby/1.6/mutex_m.rb:104:in `initialize': wrong # of arguments (0 for 1) (ArgumentError)
	  from /usr/lib/ruby/1.6/mutex_m.rb:104:in `initialize'
	  from /usr/lib/ruby/1.6/mutex_m.rb:50:in `mu_extended'
	  from /usr/lib/ruby/1.6/mutex_m.rb:34:in `extend_object'
	  from -e:1:in `extend'
	  from -e:1

-- 

 やまだ あきら <URL:http://arika.org/ruby/>
 (akira / arika.org, akira / debian.org or akira / ruby-lang.org)