While doing development it is very easy to mount your code on different VMs but this will bring you a really nasty surprise: the virtual environments created by tox cannot be used cross platform and your will start getting errors such "bad interpreter"
For example my main development machine is OS X and I do run two VMs using Parallels, one with Windows and one with Ubuntu. Both of them are mounting my entire home directory so I can access my source-code on each of them without having to synchronize it.
We need to find a way to prevent this from happening, for example if I can convince tox to include the platform name in the environment directory name, this would not happen.
.tox/py26.linux/ .tox/py26.osx/ .tox/py26.windows/ .tox/py27.linux/