How can I develop in a protected container environment?

When doing development work on my MacBook, I find myself installing so much stuff that things can get out of hand very quickly. I have a ton of dot-files in my home directory, and several package managers. I fear that there will be an issue some day that might blossom into a system reinstallation.

I know that I can use VirtualBox with some flavor of Linux to do development in a protected environment. I also get the benefits of being able to store snapshots, reconfigure the hardware, etc. However, I'd like to develop specifically on OSX.

The only solution I can think of is purchasing another copy of OSX and using that in a virtual machine. I don't mind whether it's a jail, Docker container, VM, etc. Do I have any options that don't involve purchasing OSX?