I forked Corinne Krych’s repository for building RPMs for Swift; hers worked great for the version she has in the swift.spec file, but at some point it stopped working for Swift 3. I made some changes to get it to work and have finally gotten it to build a full RPM of Swift 3.
I have submitted a pull request to her repo at https://github.com/corinnekrych/swift-rpm. My version is https://github.com/tachoknight/swift-rpm; I built it against Fedora 24, up-to-date literally as of today.
Hope this helps folks get Swift going on Fedora/RHL/RPM-based flavors of Linux.
All thanks to Corinne Krych for the original project.