package sgml-base 1.26+nmu1ubuntu1 failed to install/upgrade: ErrorMessage: subprocess installed post-installation script returned error exit status 1

[Ben Bolker]

upgrading from 10.04 to 12.04 (can't think of other particularly helpful details, sorry)

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: sgml-base 1.26+nmu1ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-42.95-generic 2.6.32.59+drm33.24
Uname: Linux 2.6.32-42-generic i686
ApportVersion: 2.0.1-0ubuntu14
Architecture: i386
Date: Fri Nov 2 15:48:54 2012
Dependencies:

ErrorMessage: ErrorMessage: subprocess installed post-installation script returned error exit status 1
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
PackageArchitecture: all
SourcePackage: sgml-base
Title: package sgml-base 1.26+nmu1ubuntu1 failed to install/upgrade: ErrorMessage: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to precise on 2012-11-02 (0 days ago)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.