TracDuplicates is a plugin for trac that will allow to dupe a bug against another generating "Marked" comments like bugzilla does in both affected bugs.
easy_install http://svn.tn123.ath.cx/trachack/TracDuplicates/0.10/
Enable tracduplicates.web_ui.
http://svn.tn123.ath.cx/trachack/TracDuplicates/0.10/
BSD-style license
This plugin redirects ticket.cs to duplicates_ticket.cs within the corresponding e.g.