As described in this previous answer (thanks Fernando!), the "installer" shell script which WANDisco provide is actually just installing a standard APT repository. Although they ask for your details before you can download the script, there seem to be no terms and conditions attached to using their repository without doing so.
The below should add the repository on 12.04 Precise (the repository doesn't contain a Source directory, which the add-apt-repository command assumes it will, so I have used a slightly different method).
sudo sh -c 'echo "# WANdisco Open Source Repo" >> /etc/apt/sources.list.d/WANdisco.list'
sudo sh -c 'echo "deb http://opensource.wandisco.com/ubuntu precise svn18" >> /etc/apt/sources.list.d/WANdisco.list'
wget -q http://opensource.wandisco.com/wandisco-debian.gpg -O- | sudo apt-key add -
sudo apt-get update
To confirm that the new subversion package has been detected, run:
apt-cache show subversion | grep '^Version:'
If the 1.8 package is listed, you should then be able to install as normal:
sudo apt-get install subversion
In order to expand Sylvain Pineaus answer a bit: I had the same problem as OP and I solved it like this:
I added the following lines at the end of /etc/apt/sources.list:
# REMEMBER TO DELETE THIS AFTER SVN 1.7 is installed
deb http://extras.ubuntu.com/ubuntu saucy main
deb http://de.archive.ubuntu.com/ubuntu/ saucy main universe restricted multiverse
Now remove the svn packages with version 1.8
sudo apt-get remove subversion libsvn1
update the sources
sudo apt-get update
and install the correct versions
sudo apt-get install subversion=1.7.9-1+nmu6ubuntu3 libsvn1=1.7.9-1+nmu6ubuntu3
Now we need to fix the version of the packages by
echo subversion hold | sudo dpkg --set-selections
echo libsvn1 hold | sudo dpkg --set-selections
echo libserf1 hold | sudo dpkg --set-selections
The libserf1 is needed by subversion or libsvn1 and is now (in 14.04) called libserf-1-1, I guess.
Now remove the lines of /etc/apt/sources.list that were added and update the sources once again (just to be sure)
sudo apt-get update
Best Answer
As of Ubuntu 12.10, subversion 1.7 is available as part of the distribution. Subversion can be installed using apt-get.
For earlier versions of Ubuntu, there is a ppa available at subversion-1.7. The repository can be added as follows:
To get the latest version of subversion update and upgrade the repository.
I needed to also do a dist-upgrade.
I'm assuming that you already have subversion installed, if not: