IntegrityError: (1062, "Duplicate entry 'kbwood-1-query_constrain' for key 1")

How to Reproduce

While doing a GET operation on /query, Trac issued an internal error.

IntegrityError: (1062, "Duplicate entry 'kbwood-1-query_constrain' for key 1")

System Information

|| Trac || 0.11rc1 ||

|| Python || 2.4.4 (#2, Apr 26 2007, 00:02:45) [GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] ||

|| setuptools || 0.6c8 ||

|| MySQL || server: "5.0.51a-3-log", client: "5.0.51a", thread-safe: 1 ||

|| MySQLdb || 1.2.2 ||

|| Genshi || 0.4.4 ||

|| Pygments || 0.9 ||

|| Subversion || 1.4.4 (r25188) ||

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/Trac-0.11rc1-py2.4.egg/trac/web/main.py", line 417, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.4/site-packages/Trac-0.11rc1-py2.4.egg/trac/web/main.py", line 222, in dispatch
    req.session.save()
  File "/usr/lib/python2.4/site-packages/Trac-0.11rc1-py2.4.egg/trac/web/session.py", line 93, in save
    "VALUES(%s,%s,%s,%s)", attrs)
  File "/usr/lib/python2.4/site-packages/Trac-0.11rc1-py2.4.egg/trac/db/util.py", line 57, in executemany
    return self.cursor.executemany(sql_escape_percent(sql), args)
  File "/usr/lib/python2.4/site-packages/Trac-0.11rc1-py2.4.egg/trac/db/util.py", line 57, in executemany
    return self.cursor.executemany(sql_escape_percent(sql), args)
  File "/var/lib/python-support/python2.4/MySQLdb/cursors.py", line 218, in executemany
    r = self._query('\\n'.join([query[:p], ',\\n'.join(q), query[e:]]))
  File "/var/lib/python-support/python2.4/MySQLdb/cursors.py", line 312, in _query
    rowcount = self._do_query(q)
  File "/var/lib/python-support/python2.4/MySQLdb/cursors.py", line 276, in _do_query
    db.query(q)
IntegrityError: (1062, "Duplicate entry 'kbwood-1-query_constrain' for key 1")