I am running a clean install of OS X El Capitan (10.11.1 - 15B42) and trying to build a custom plugin for Apple Messages application following the instructions here and here. I copy the custom plugin I built and the one provided by Apple in the examples (IRCServicePlugin) to "~/Library/Messages/PlugIns" folder and kill imagent service by running "killall imagent". Once I open up Messages app and try to add a service, my custom service or the IRCServicePlugin's service doesn't show up in the "Account Type" list. This use to work before but it appears to be broken with the El Capitan update.
Can someone please clarify whether the support for IMServicePlugins are dropped or this is a bug introduced in El Capitan?
This may be due Instant Message framework is deprecated since 10.9 as it says in release notes.
The Instant Message framework is superseded by the Social framework. Because the Messages application no longer provides functionality that the Instant Message framework requires, in OS X v10.9 and later this framework always returns an empty buddy list.