Samba upgrade fails during Lucid->Precise upgrade; "package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: ErrorMessage: subprocess installed post-installation script returned error exit status 126"

[Peter Fajner]

During a server upgrade from 10.04 to 12.04 over ssh, the upgrade failed due to a Samba upgrade error. The bug report that Ubuntu generated is attached.

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: samba4 4.0.0~alpha18.dfsg1-4ubuntu2
ProcVersionSignature: Ubuntu 2.6.32-41.94-generic 2.6.32.59+drm33.24
Uname: Linux 2.6.32-41-generic i686
NonfreeKernelModules: nvidia
ApportVersion: 2.0.1-0ubuntu17.3
Architecture: i386
Date: Thu Jul 18 16:17:20 2013
ErrorMessage: ErrorMessage: subprocess installed post-installation script returned error exit status 126
InstallationMedia: Ubuntu 10.04.1 LTS "Lucid Lynx" - Release i386 (20100816.1)
MarkForUpload: True
SourcePackage: samba4
Title: package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: ErrorMessage: subprocess installed post-installation script returned error exit status 126
UpgradeStatus: Upgraded to precise on 2013-07-18 (0 days ago)