xapian-index crashes whilst machine unattended

[jason-at-work]

Binary package hint: apt-xapian-index

Machine left unattended over weekend, this error visible on screen on return to work Monday.
Runs Karmic 9.10 but is a recent upgrade from Jaunty 9.04.

$ lsb_release -rd
Description: Ubuntu 9.10
Release: 9.10

$ apt-cache policy apt-xapian-index
apt-xapian-index:
  Installed: 0.21ubuntu2
  Candidate: 0.21ubuntu2
  Version table:
 *** 0.21ubuntu2 0
        500 http://gb.archive.ubuntu.com karmic/main Packages
        100 /var/lib/dpkg/status

ProblemType: Crash
Architecture: i386
Date: Sun Nov 8 06:47:01 2009
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/sbin/update-apt-xapian-index
InterpreterPath: /usr/bin/python2.6
NonfreeKernelModules: nvidia
Package: apt-xapian-index 0.21ubuntu2
PackageArchitecture: all
ProcCmdline: /usr/bin/python /usr/sbin/update-apt-xapian-index --quiet
ProcEnviron:
 PATH=(custom, no user)
 SHELL=/bin/sh
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
PythonArgs: ['/usr/sbin/update-apt-xapian-index', '--quiet']
SourcePackage: apt-xapian-index
Title: update-apt-xapian-index crashed with OSError in <module>()
Traceback:
 Traceback (most recent call last):
   File "/usr/sbin/update-apt-xapian-index", line 613, in <module>
     lockfd = os.open(XAPIANDBLOCK, os.O_RDWR | os.O_CREAT)
 OSError: [Errno 13] Permission denied: '/var/lib/apt-xapian-index/update-lock'
Uname: Linux 2.6.31-14-generic i686
UserGroups: adm admin cdrom dialout lpadmin plugdev sambashare

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make Ubuntu better. This particular crash has already been reported and is a duplicate of bug #263187, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.