That's because twiki 1:4.1.2-3.1ubuntu1 fails to install:
Setting up twiki (1:4.1.2-3.1ubuntu1) ...
Adding password for user TWikiGuest
reloading apache2 config
apache2: Syntax error on line 185 of /etc/apache2/apache2.conf: Syntax error on line 1 of /etc/apache2/mods-enabled/xmlrpc.load: Cannot load /usr/lib/apache2/modules/mod_xmlrpc.so into server: /usr/lib/apache2/modules/mod_xmlrpc.so: undefined symbol: xmlrpc_registry_new
...fail!
dpkg: error processing twiki (--configure):
subprocess post-installation script returned error exit status 1
That's because twiki 1:4.1.2-3.1ubuntu1 fails to install:
Setting up twiki (1:4.1. 2-3.1ubuntu1) ... apache2. conf: Syntax error on line 1 of /etc/apache2/ mods-enabled/ xmlrpc. load: Cannot load /usr/lib/ apache2/ modules/ mod_xmlrpc. so into server: /usr/lib/ apache2/ modules/ mod_xmlrpc. so: undefined symbol: xmlrpc_registry_new
Adding password for user TWikiGuest
reloading apache2 config
apache2: Syntax error on line 185 of /etc/apache2/
...fail!
dpkg: error processing twiki (--configure):
subprocess post-installation script returned error exit status 1