Vanishing swiftdoc, swiftsourceinfo, swift module files

In prep for a push this evening did the usual clean and rebuild. But now I'm getting errors that it can't find files with .swiftdoc, swiftsourceinfo, and swiftmodule files. The few postings I can find about that said that reinstalling xcode fixed it, well , not i my case. Any ideas short of reconstructing the entire project from scratch?