package libapache2-mod-security2 2.9.0-1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1

[fluffy]

During do-distribution-upgrade from precise to 16.04.1

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: libapache2-mod-security2 2.9.0-1
Uname: Linux 4.5.5-x86_64-linode69 x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: i386
Date: Sun Jul 31 12:44:46 2016
DuplicateSignature:
 package:libapache2-mod-security2:2.9.0-1
 Setting up libapache2-mod-authnz-external (3.3.2-0.1) ...
 dpkg: error processing package libapache2-mod-authnz-external (--configure):
  subprocess installed post-installation script returned error exit status 1
ErrorMessage: subprocess installed post-installation script returned error exit status 1
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.1
 apt 1.2.12~ubuntu16.04.1
SourcePackage: modsecurity-apache
Title: package libapache2-mod-security2 2.9.0-1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
UpgradeStatus: Upgraded to xenial on 2016-07-31 (0 days ago)
modified.conffile..etc.apache2.mods-available.security2.conf: [deleted]
modified.conffile..etc.apache2.mods-available.security2.load: [deleted]

[Launchpad Janitor (janitor)]

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

[QuentinHartman (qhartman)]

In looking at the postinst script /var/lib/dpkg/info/libapache2-mod-security2.postinst, it appears that it is trying to enable the "security2" module, but that module does not exist in /etc/apache2/mods-available, so I don't think it will ever succeed. If you modify that script so that chunk is a no-op, it will succeed and "work", allowing installation of other packages to continue. I don't yet know if there are bad side-effects as I would expect that module to exist.

I commented out the "apache2_invoke..." line and added 'echo "Disabled stuff here"' to make bash happy.

It looks like there are quite a few changes with apache2 and it's modules between 14.04 and 16.04, so this workaround may break all the things. Proceed with caution.

[fluffy (fluffy)]

Yeah, my workaround to get my server back up was to just uninstall all the affected modules, since I wasn't really using them anyway.