Cannot install Subversion on Ubuntu with Apache 2.4.10: undefined symbol: ap_hook_force_authn

Symptoms

Cannot install Subversion on Ubuntu:

# apt-get install subversion libapache2-sv

apache2: Syntax error on line 140 of /etc/apache2/apache2.conf: Syntax error on
line 2 of /etc/apache2/mods-enabled/authz_svn.load: Cannot load
/usr/lib/apache2/modules/mod_authz_svn.so into server:
/usr/lib/apache2/modules/mod_authz_svn.so: undefined symbol: ap_hook_force_authnapache2: Syntax error on line 140 of /etc/apache2/apache2.conf: Syntax error on
line 2 of /etc/apache2/mods-enabled/authz_svn.load: Cannot load
/usr/lib/apache2/modules/mod_authz_svn.so into server:
/usr/lib/apache2/modules/mod_authz_svn.so: undefined symbol: ap_hook_force_authn

Cause

This is bug in Subversion package discussed here .

Resolution

Downgrade Apache to version 2.4.7 manually:

1. Make sure that default Ubuntu 14.04 repositories are enabled:

# cat /etc/apt/sources.list
deb http://archive.ubuntu.com/ubuntu trusty main restricted universe
deb http://archive.ubuntu.com/ubuntu trusty-updates main restricted universe
deb http://security.ubuntu.com/ubuntu trusty-security main restricted universe multiverse
deb http://archive.canonical.com/ubuntu trusty partner


2. Create temp dir, cd to it and download all required packages:

# mkdir tempdir
# cd tempdir/
# apt-get download apache2=2.4.7-1ubuntu4.13
# apt-get download apache2-bin=2.4.7-1ubuntu4.13
# apt-get download apache2-data=2.4.7-1ubuntu4.13
# apt-get download apache2-doc=2.4.7-1ubuntu4.13
# apt-get download apache2-mpm-event=2.4.7-1ubuntu4.13
# apt-get download apache2-mpm-prefork=2.4.7-1ubuntu4.13
# apt-get download apache2-utils=2.4.7-1ubuntu4.13
# apt-get download libapache2-mod-proxy-psa_2.4.7-ubuntu14.04.16022012



3. Create backup of enabled modules:

# cp -r /etc/apache2/mods-enabled /root/mods-enabled



4. Install apache packages:

# dpkg -i apache2_2.4.7-1ubuntu4.13_amd64.deb

# dpkg -i apache2-*

# dpkg -i libapache2-mod-proxy-psa*

4. Set hold flag to apache packages:

# apt-mark hold ^apache2-*