Note that in spite of supporting Ubuntu only, you can run the 4.0 version in Debian Stretch without any problems. Just download the package, unpack it and add t

Note that in spite of supporting Ubuntu only, you can run the 4.0 version in Debian Stretch without any problems. Just download the package, unpack it and add the bin/ subdirectory to your $PATH. Edit: REPL stil doesn't allow importing Glibc by default, you need to specify the include path manually (e.g. swift -I /opt/swift-4.0-RELEASE-ubuntu16.10/usr/lib/swift/clang/include/).