do-release-upgrade crashed with AttributeError in distUpgrade(): 'SystemError' object has no attribute 'encode'

[Karma Dorje]

$ lsb_release -rd
Description: Ubuntu Saucy Salamander (development branch)
Release: 13.10

$ apt-cache policy ubuntu-release-upgrader-core
ubuntu-release-upgrader-core:
  Installed: 1:0.196
  Candidate: 1:0.196
  Version table:
 *** 1:0.196 0
        500 http://archive.ubuntu.com/ubuntu/ saucy/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Crash
DistroRelease: Ubuntu 13.10
Package: ubuntu-release-upgrader-core 1:0.196
ProcVersionSignature: Ubuntu 3.10.0-2.9-generic 3.10.0
Uname: Linux 3.10.0-2-generic x86_64
ApportVersion: 2.10.2-0ubuntu3
Architecture: amd64
CrashDB: ubuntu
Date: Fri Jul 5 01:19:41 2013
ExecutablePath: /usr/bin/do-release-upgrade
InstallationDate: Installed on 2012-09-30 (277 days ago)
InstallationMedia: Ubuntu 12.04.1 LTS "Precise Pangolin" - Release amd64 (20120817.1)
InterpreterPath: /usr/bin/python3.3
MarkForUpload: True
PackageArchitecture: all
ProcCmdline: /usr/bin/python3 /usr/lib/ubuntu-release-upgrader/do-partial-upgrade --frontend=DistUpgradeViewGtk3
PythonArgs: ['/usr/bin/do-release-upgrade', '--frontend=DistUpgradeViewGtk3']
SourcePackage: ubuntu-release-upgrader
Title: do-release-upgrade crashed with AttributeError in distUpgrade(): 'SystemError' object has no attribute 'encode'
UpgradeStatus: Upgraded to saucy on 2013-05-06 (59 days ago)
UserGroups:

VarLogDistupgradeTermlog: