Unknown error pops up out of nowhere

[anonymous]

Traceback (most recent call last):
  File "/var/lib/python-support/python2.4/trac/web/main.py", line 387, in dispatch_request
    dispatcher.dispatch(req)
  File "/var/lib/python-support/python2.4/trac/web/main.py", line 191, in dispatch
    chosen_handler = self._pre_process_request(req, chosen_handler)
  File "/var/lib/python-support/python2.4/trac/web/main.py", line 263, in _pre_process_request
    chosen_handler = f.pre_process_request(req, chosen_handler)
  File "/var/lib/python-support/python2.4/trac/versioncontrol/api.py", line 73, in pre_process_request
    self.get_repository(req.authname) # triggers a sync if applicable
  File "/var/lib/python-support/python2.4/trac/versioncontrol/api.py", line 101, in get_repository
    repos = self._connector.get_repository(rtype, rdir, authname)
  File "/var/lib/python-support/python2.4/trac/versioncontrol/svn_fs.py", line 260, in get_repository
    crepos = CachedRepository(self.env.get_db_cnx(), repos, None, self.log)
  File "/var/lib/python-support/python2.4/trac/versioncontrol/cache.py", line 39, in __init__
    self.sync()
  File "/var/lib/python-support/python2.4/trac/versioncontrol/cache.py", line 63, in sync
    cursor.execute("SELECT name, value FROM system WHERE name IN (%s)" %
  File "/var/lib/python-support/python2.4/trac/db/util.py", line 51, in execute
    return self.cursor.execute(sql)
  File "/var/lib/python-support/python2.4/trac/db/sqlite_backend.py", line 56, in execute
    args or [])
  File "/var/lib/python-support/python2.4/trac/db/sqlite_backend.py", line 48, in _rollback_on_error
    return function(self, *args, **kwargs)
ProgrammingError: library routine called out of sequence

[Emmanuel Blot]

It is likely to be a duplicate of #4331 and some other tickets, although the lack of useful information (Trac version, SQLite version …) may lead to a wrong diagnosis.

[Christian Boos]

" self.get_repository(req.authname) # triggers a sync if applicable"

That's 0.10.3, possibly earlier. Please upgrade to 0.10.4 and maybe check that you've got a reasonably recent SQLite (compiled with multithreading support) and PySqlite.