do-release-upgrade crashed with IOError in init_proxy() with invalid looking proxy setting

[Robert B]

Binary package hint: update-manager

$ lsb_release -rd
Description: Ubuntu lucid (development branch)
Release: 10.04
$ apt-cache policy update-manager
update-manager:
  Installed: 1:0.134.3
  Candidate: 1:0.134.3
  Version table:
 *** 1:0.134.3 0
        100 /var/lib/dpkg/status

Seems to be python 2.6-specific issue since unattended-upgrades also crashes.

ProblemType: Crash
DistroRelease: Ubuntu 10.04
Package: update-manager-core 1:0.134.3
ProcVersionSignature: Ubuntu 2.6.32-21.31-generic-pae 2.6.32.11+drm33.2
Uname: Linux 2.6.32-21-generic-pae i686
Architecture: i386
Date: Thu Apr 15 07:34:56 2010
ExecutablePath: /usr/bin/do-release-upgrade
InstallationMedia: Ubuntu 10.04 "Lucid Lynx" - Alpha i386 (20100213)
InterpreterPath: /usr/bin/python2.6
ProcCmdline: /usr/bin/python2.6 /usr/lib/update-manager/check-new-release -q
ProcEnviron:
 PATH=(custom, no user)
 LANG=C
 SHELL=/bin/bash
PythonArgs: ['/usr/lib/update-manager/check-new-release', '-q']
SourcePackage: update-manager
Title: do-release-upgrade crashed with IOError in init_proxy()
UserGroups:

[dino99 (9d9)]

This version is no more supported