No dependencies needed, besides the packages SwiftPM will download.
On Debian based Linux distributions you need a few packages. Install them using apt:
sudo apt install openssl libssl-dev libcurl4-openssl-dev libavahi-compat-libdnssd-dev
Linux ARM / Raspberry Pi (Raspbian Stretch)
There are currently no official binaries from swift.org targetting ARM / Raspbian, however there’s an active community working on Swift on ARM. You can install binaries from their repository:
curl -s https://packagecloud.io/install/repositories/swift-arm/release/script.deb.sh | sudo bash sudo apt install swiftlang
Now that you have all the dependencies installed, you should be able to build and run the demo. For optimal performance, use a release build:
swift run -c release hap-demo