No Plugins (HandlerSocket plugin) in percona-server-5.1 LUCID deb package

In tha package percona-server-server-5.1 for LUCID (ubuntu 10.04) amd64 there is no plugins and also HandlerSocket.so plugin, but for maverick (ubuntu 10.10) it does.

How I can install plugins in Ubuntu 10.04 (lucid)?