My project uses buildout to do primarily two things: automatically fetch dependencies and create scripts; and setup cron jobs (on deployment machines) using the usercrontab buildout recipe.

But buildout is not yet available for Python 3.

So I would like to consider alternatives for buildout. I know that both virtualenv and pip work on Python 3 - but what is the preferred tool to automate the build toolchain (of creating virtualenv, and automatically installing/upgrading deps)? There is fabric, paver, and so on. What is your preferred tool of choice in this case? It must work seamlessly on both Windows and *nix.