TypeError: 'hgwebdir' object is not callable

There may be a number of scenarios under which this error can happen but in my case it was because I was using an incompatible version hgwebdir.cgi. After installing Mercurial 0.9.4 I downloaded hgwebdir.cgi from here (which at the time of writing was for Mercurial 1.0). To fix the problem I had to use the version of hgwebdir.cgi that came with the Mercurial 0.9.4 install. On Ubuntu you’ll find it here /usr/share/doc/mercurial/examples/hgwebdir.cgi.

In order to load modules you no longer have to add a LoadModule directive to the main config file. Instead, when you install a module using apt-get a file call <module_name>.load is created in the directory /etc/apache2/mods-available. If the module has any configuration associated with it then a seperate file called <module_name>.conf is also created in the same directory. To enable the module you create a symbolic link to each of these two files in the directory /etc/apache2/mods-enabled. When Apache starts it simply includes all the files in this directory. The commands a2enmod and a2dismod can manage all this for you if you don’t want to create/remove the links yourself, e.g. sudo a2enmod userdir, sudo a2dismod userdir.

Virtual hosts are managed in a very similar fashion. To create a new virtual host create a file in the directory /etc/apache2/sites-available containing the VirtualHost directive. To enable this host you create a symbolic link to this file in the directory /etc/apache2/sites-enabled. The commands a2ensite and a2dissite can manage all this for you, e.g. sudo a2ensite subversion.