update-manager: emacs-snapshot-gtk fails to install upgrading from ubuntu dapper to edgy

Originally reported using reportbug. Filing by proxy.

The original bug report follows:

From: Michael Rowe <email address hidden>
To: Ubuntu Bug Tracking System <email address hidden>
Subject: update-manager: emacs-snapshot-gtk fails to install upgrading from ubuntu dapper to edgy
Date: Sat, 30 Sep 2006 10:11:23 +1000
X-Mailer: reportbug 3.21.2ubuntu1

Package: update-manager
Version: 0.44.12
Severity: normal

Running gksu "update-manager -c -d" to upgrade a dapper machine to edgy, I got the following
message during package installation:

    subprocess post-installation script returned error exit status 1

-- System Information:
Debian Release: testing/unstable
  APT prefers edgy-updates
  APT policy: (500, 'edgy-updates'), (500, 'edgy-security'), (500, 'edgy')
Architecture: amd64 (x86_64)
Shell: /bin/sh linked to /bin/dash
Kernel: Linux 2.6.15-27-amd64-generic
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8)

Versions of packages update-manager depends on:
ii gconf2 2.14.0-1ubuntu2 GNOME configuration database syste
ii gksu 1.9.3-1ubuntu2 graphical frontend to su
ii iso-codes 0.52-1 ISO language, territory, currency
ii lsb-release 3.1-10ubuntu4 Linux Standard Base version report
ii python 2.4.3-11ubuntu3 An interactive high-level object-o
ii python-apt 0.6.19ubuntu5 Python interface to libapt-pkg
ii python-dbus 0.71-2ubuntu1 simple interprocess messaging syst
ii python-glade2 2.10.1-0ubuntu1 GTK+ bindings: Glade support
pn python-gnupginterface <none> (no description available)
ii python2.4 2.4.3-8ubuntu1 An interactive high-level object-o
ii synaptic 0.57.11ubuntu10 Graphical package manager
ii unattended-upgrades 0.1ubuntu6 Install security upgrades automati

Versions of packages update-manager recommends:
pn python-gnome2 <none> (no description available)

-- no debconf information