I've been testing a few plugins recently and decided to do most of it in virtual machines managed by Vagrant. As I was installing DokuWiki frequently into these VMs, but I still wanted it to be visible in my host operating system where I was doing the development (so I could inspect changes as the plugin operated) I wrapped up the whole environment and the scripts used to install a fresh working copy of DokuWiki into a GitHub project:
https://github.com/iainhallam/vagrant-dokuwiki-plugin
If you're working on a plugin, you can create the appropriate directories above the plugin files, download this repo, and write a short BASh script to do any configuration your plugin needs, then you have a reproducible environment for testing the plugin just by running the command
vagrant up[/m] and pointing your browser at [m]localhost:10080.
If you make a mess of the installation, you can use
vagrant destroy and start again. (If you mess up the plugin files, I'm assuming you're using some kind of source code versioning...).
Anyway, I thought it might be useful to anyone who does a lot of testing or plugin development.