Cannot sync with svn

[mikhail.b@…]

Traceback (most recent call last):
  File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 387, in dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 191, in dispatch
    chosen_handler = self._pre_process_request(req, chosen_handler)
  File "/usr/lib/python2.4/site-packages/trac/web/main.py", line 263, in _pre_process_request
    chosen_handler = f.pre_process_request(req, chosen_handler)
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/api.py", line 73, in pre_process_request
    self.get_repository(req.authname) # triggers a sync if applicable
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/api.py", line 101, in get_repository
    repos = self._connector.get_repository(rtype, rdir, authname)
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/svn_fs.py", line 260, in get_repository
    crepos = CachedRepository(self.env.get_db_cnx(), repos, None, self.log)
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/cache.py", line 34, in __init__
    self.sync()
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/cache.py", line 91, in sync
    for path,kind,action,base_path,base_rev in changeset.get_changes():
  File "/usr/lib/python2.4/site-packages/trac/versioncontrol/svn_fs.py", line 648, in get_changes
    root = fs.revision_root(self.fs_ptr, self.rev, pool())
  File "/usr/lib/python2.4/site-packages/libsvn/fs.py", line 217, in svn_fs_revision_root
    return apply(_fs.svn_fs_revision_root, args)
SubversionException: ("Can't set position pointer in file '/var/svn/db/revs/862': Invalid argument", 22)

[Emmanuel Blot]

Please specify which version of Trac you're using.