I never bother. I find it much easier and much less hassle to use VMs. With Fusion, you can create snapshots, try something out and revert back if it doesn't work out.
This way my primary OS stays as clean as possible (text editor, browser, fusion) and my VMs can be my messy playground.
Don't get me wrong, brew and ports are great but their very existence makes we wary of venturing too far down the rabbit hole of development directly on OSX.
Not to mention you can now run OSX within OSX using VMWare and the like - easy way to run multiple speculative profile branches and snapshot back to a known good state whenever you want.
I tend to use Linux while developing, however so I do OSX host, Linux guest -> deploy to fabric or cloud host for system/performance testing.
This way my primary OS stays as clean as possible (text editor, browser, fusion) and my VMs can be my messy playground.
Don't get me wrong, brew and ports are great but their very existence makes we wary of venturing too far down the rabbit hole of development directly on OSX.