Issue #3787 has been updated by Akira Matsuda. I just got the same error on my machine (Mac OSX 10.6) with both Ruby 1.8.7 and 1.9.2. % ruby -d -v -rsocket -e "TCPSocket.new '::1', 1200" ruby 1.8.7 (2010-08-16 patchlevel 302) [i686-darwin10] Exception `Errno::ECONNREFUSED' at -e:1 - Connection refused - connect(2) -e:1:in `initialize': Connection refused - connect(2) (Errno::ECONNREFUSED) from -e:1:in `new' from -e:1 % ruby -d -v -rsocket -e "TCPSocket.new '::1', 1200" ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-darwin10.4.0] Exception `Errno::ECONNREFUSED' at -e:1 - Connection refused - connect(2) -e:1:in `initialize': Connection refused - connect(2) (Errno::ECONNREFUSED) from -e:1:in `new' from -e:1:in `<main>' ---------------------------------------- http://redmine.ruby-lang.org/issues/show/3787 ---------------------------------------- http://redmine.ruby-lang.org