[joshavant]

I've done a small amount of work for a Swift-based project that was packaged as CLI program. FWIW, it was a really difficult project to develop for.

This mainly had to do with the fact that the project had to be built from a hacky Rakefile, not Xcode. This was because Xcode would embed the Swift runtime only into an .app or .ipa file (because projects need to be shipped with the same Swift version used to build it, thanks to lack of ABI stability). But, as a CLI tool, there was no .app bundle - only a single executable. One downfall.

So, now that you're not using the Xcode IDE to build + run the project, you can't use the debugging IDE tooling in Xcode, making the development process that much harder. Another downfall.

I haven't checked if this has been fixed in recent builds (this all happened back in January), but figure that these are the kind of issues you're going to encounter, until the Swift language is a little more stable + proper tooling evolves.

That said, it seems pretty clear the future is Swift, so it would be better to start building experience with it sooner rather than later!