do-release-upgrade LTS 12.04.5 -> 14.04.1 --- package spamassassin 3.4.0-1ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2

[Michael T.]

Part of the upgrade output:

Installing new version of config file /etc/cron.daily/spamassassin ...
Installing new version of config file /etc/init.d/spamassassin ...
Warning: The home dir /var/lib/spamassassin you specified already exists.
Adding system user `debian-spamd' (UID 116) ...
Adding new group `debian-spamd' (GID 125) ...
Adding new user `debian-spamd' (UID 116) with group `debian-spamd' ...
The home directory `/var/lib/spamassassin' already exists. Not copying from `/etc/skel'.
adduser: Warning: The home directory `/var/lib/spamassassin' does not belong to the user you are currently creating.
-su: 33: [: -eq: unexpected operator
-su: 129: Syntax error: "(" unexpected (expecting "fi")
dpkg: error processing package spamassassin (--configure):
 subprocess installed post-installation script returned error exit status 2
Setting up libxml-parser-perl (2.41-1build3) ...
No apport report written because MaxReports is reached already

ProblemType: Package
DistroRelease: Ubuntu 14.04
Package: spamassassin 3.4.0-1ubuntu2.1
ProcVersionSignature: Ubuntu 3.2.0-76.111-generic 3.2.66
Uname: Linux 3.2.0-76-generic x86_64
ApportVersion: 2.14.1-0ubuntu3.6
Architecture: amd64
Date: Sat Feb 14 17:30:39 2015
DuplicateSignature: package:spamassassin:3.4.0-1ubuntu2.1:subprocess installed post-installation script returned error exit status 2
ErrorMessage: subprocess installed post-installation script returned error exit status 2
PackageArchitecture: all
SourcePackage: spamassassin
Title: package spamassassin 3.4.0-1ubuntu2.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 2
UpgradeStatus: Upgraded to trusty on 2015-02-14 (0 days ago)
mtime.conffile..etc.default.spamassassin: 2010-03-24T15:51:01
mtime.conffile..etc.spamassassin.local.cf: 2010-04-19T16:20:10

[Michael T. (p-ubuntu-one)]

found a hint somewhere to change

/var/lib/dpkg/info/spamassassin.postinst

Change

    su - $OWNER -c "sa-update --gpghomedir /var/lib/spamassassin/sa-update-keys \
        --import /usr/share/spamassassin/GPG.KEY"

to

    su - $OWNER -s /bin/bash -c "sa-update --gpghomedir /var/lib/spamassassin/sa-update-keys \
        --import /usr/share/spamassassin/GPG.KEY"

now it works
  dpkg --configure spamassassin

maybe a side effect of new? standard shell /bin/sh -> dash and incompatible /etc/profile

[Bryce Harrington (bryce)]

Sounds similar to https://bugs.launchpad.net/ubuntu/+source/spamassassin/+bug/1310307