I am running my app from xcode to my iOS device and I get this and black screen on iOS device.
Console text:
dyld: Library not loaded: @rpath/libswif
I already had the Runpath Search Paths set correctly, but it still didn't work. @Justin Domnitz's answer put me on the right track: Setting "Always Embed Swift Standard Libraries" to Yes in my target's build settings did the trick for me.