[CJefferson]

This is exactly what Nix does, but not all libraries are currently 'Nixified', and the ones which are aren't consistent.

Apple doesn't help this -- they want you to just install xcode and the most recent SDK and nothing else.

[matt4077]

well, there's xcode-select to chose the SDK you want which kinda implies the availability of multiple – currently for example swift 2.2 and 3.0.

I'm tempted by the "1-environment" idea but homebrew has done such an excellent job in comparison to fink/port, I';; stay loyal. Also wondering if those two projects couldn't profit from some code sharing?