How can i install swift 4.1 on ubuntu 18.04?
@kindlychung See this post. Long story short: There's ongoing work to setup CI for 18.04 and @tkremenek said they hope to have pre-built 18.04 images for Swift 4.2.
If you're willing to build Swift from source yourself you should be able to do that today on 18.04.
This may be another option that may make a lot of sense in a server setup anyways:
docker run --rm -it swift:4.1.0 swift --version
Seems like a lot of people still do this with even older distros.