Comment 7 for bug 877627

After remove both files and rebuild update-apt-xapian-index -v have error:

2012-05-11 11:16:18,627 - softwarecenter.ui.gtk3.app - INFO - setting up proxy 'None'
2012-05-11 11:16:18,633 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2012-05-11 11:16:18,812 - softwarecenter.ui.gtk3.app - INFO - building local database
2012-05-11 11:16:18,813 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
2012-05-11 11:16:19,523 - softwarecenter.db.update - WARNING - Cannot write to '/var/cache/software-center/xapian'.
2012-05-11 11:16:19,523 - softwarecenter.db.update - WARNING - Please check you have the relevant permissions.
2012-05-11 11:16:19,523 - softwarecenter.db.database - INFO - open() database: path=None use_axi=True use_agent=True
2012-05-11 11:16:19,822 - softwarecenter.backend.reviews - WARNING - Could not get usefulness from server, no username in config file
2012-05-11 11:16:20,460 - softwarecenter.db.pkginfo_impl.aptcache - INFO - aptcache.open()
Traceback (most recent call last):
  File "/usr/bin/software-center", line 176, in <module>
    app.run(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1343, in run
    self.show_available_packages(args)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/app.py", line 1273, in show_available_packages
    self.view_manager.set_active_view(ViewPages.AVAILABLE)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/session/viewmanager.py", line 149, in set_active_view
    view_widget.init_view()
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/availablepane.py", line 133, in init_view
    SoftwarePane.init_view(self)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/panes/softwarepane.py", line 214, in init_view
    self.icons, self.show_ratings)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/views/appview.py", line 69, in __init__
    self.helper = AppPropertiesHelper(db, cache, icons)
  File "/usr/share/software-center/softwarecenter/ui/gtk3/models/appstore2.py", line 107, in __init__
    softwarecenter.paths.APP_INSTALL_PATH)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 255, in parse_applications_menu
    category = self._parse_menu_tag(child)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 444, in _parse_menu_tag
    query = self._parse_include_tag(element)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 402, in _parse_include_tag
    xapian.Query.OP_AND)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 341, in _parse_and_or_not_tag
    operator_elem, xapian.Query(), xapian.Query.OP_OR)
  File "/usr/share/software-center/softwarecenter/db/categories.py", line 385, in _parse_and_or_not_tag
    q = self.db.xapian_parser.parse_query(s,
  File "/usr/share/software-center/softwarecenter/db/database.py", line 170, in xapian_parser
    xapian_parser = self._get_new_xapian_parser()
  File "/usr/share/software-center/softwarecenter/db/database.py", line 196, in _get_new_xapian_parser
    xapian_parser.set_database(self.xapiandb)
  File "/usr/share/software-center/softwarecenter/db/database.py", line 162, in xapiandb
    self._db_per_thread[thread_name] = self._get_new_xapiandb()
  File "/usr/share/software-center/softwarecenter/db/database.py", line 175, in _get_new_xapiandb
    xapiandb = xapian.Database(self._db_pathname)
  File "/usr/lib/python2.7/dist-packages/xapian/__init__.py", line 3666, in __init__
    _xapian.Database_swiginit(self,_xapian.new_Database(*args))
xapian.DatabaseOpeningError: Couldn't detect type of database