I'm performing some research and analysis on bug/issue tracking databases and more specifically on how programmers and teams of programmers actually interact with them. What I'm looking for involves understanding how those databases change over time.

So what I don't need for example: is a database of all the bugs of some open source project as the bugs exist today. What I do need is a complete set of revision history for every issue/bug in the database. This would enable me to pick a specific datetime and say here were the list of all the issues/bugs that existed at that moment in time.

Anyway know of some publicly accessible issue/bug databases that expose this revision data?

Ideally, the revision would look something like this (shown for a single bug, with two revisions)

 ISSUEID  PRI  SEV  ASSIGNEDTO  MODIFIEDON      VALIDUNTIL
 1        2    2    mel         apr-1-2010:5pm  apr-1-2010:6pm
 1        2    3    steve       apr-1-2010:6pm  NULL