Good tip. Another suggestion would be to use chroot :)

That said, the best, most foolproof way of doing this really comes down to using OS X to virtualize OS X.

Or you could try cross-compiling. It seems to work here: https://github.com/swift-x/tools (which looks interesting...)

It's possible that by the end of this week, maybe next, it will be very easy indeed to compile and/or run Swift on Linux from Linux, at which point you could try LXC or a million other ways to virtualize.

Thanks for the tips! I'd love to move to LXC should an appropriate/feasible compiling solution become available :)