package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126

[Nilay Tripathi]

I was trying to install samba4 package when this problem occured. I could launch samba4 GUI app afterwards from the Unity launcher but immediately after the installation it failed to launch from the command line.
Following error:

$ samba
Unknown parameter encountered: "max log size"
Ignoring unknown parameter "max log size"
Unknown parameter encountered: "syslog"
Ignoring unknown parameter "syslog"
Unknown parameter encountered: "unix password sync"
Ignoring unknown parameter "unix password sync"
Unknown parameter encountered: "passwd program"
Ignoring unknown parameter "passwd program"
Unknown parameter encountered: "pam password change"
Ignoring unknown parameter "pam password change"
Unknown parameter encountered: "map to guest"
Ignoring unknown parameter "map to guest"
Unknown parameter encountered: "usershare allow guests"
Ignoring unknown parameter "usershare allow guests"
Unknown parameter encountered: "username map"
Ignoring unknown parameter "username map"
[2012/04/30 21:12:01, 0] ../lib/util/debug.c:578(reopen_logs_internal)
  Unable to open new log file '/var/log/samba/log.%m': Permission denied
[2012/04/30 21:12:01, 0] ../source4/smbd/server.c:366(binary_smbd_main)
  samba version 4.0.0alpha18 started.
  Copyright Andrew Tridgell and the Samba Team 1992-2012
$

ProblemType: Package
DistroRelease: Ubuntu 12.04
Package: samba4 4.0.0~alpha18.dfsg1-4ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic-pae 3.2.14
Uname: Linux 3.2.0-23-generic-pae i686
ApportVersion: 2.0.1-0ubuntu5
Architecture: i386
Date: Mon Apr 30 21:08:14 2012
ErrorMessage: subprocess installed post-installation script returned error exit status 126
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release i386 (20120423)
SourcePackage: samba4
Title: package samba4 4.0.0~alpha18.dfsg1-4ubuntu2 failed to install/upgrade: subprocess installed post-installation script returned error exit status 126
UpgradeStatus: No upgrade log present (probably fresh install)

[Apport retracing service (apport)]

Thank you for taking the time to report this crash and helping to make this software better. This particular crash has already been reported and is a duplicate of bug #982609, so is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.