LunarCmd will launch Lunar Client from the command line.
To start with default settings run
lunarcmd <lunar_version>. lunar_version can be any Lunar Client version (ex: 1.8)
To build, run
make. To install after building, run
sudo make install. You will need to have Swift installed to build.
The SwiftyJSON.swift is from https://github.com/IBM-Swift/SwiftyJSON, with a few small modifications to make building work on Linux.
To download, use the appropriate zip file from Releases. If on Linux, run the lunarcmd shell script, NOT the executable in bin/. This will set the LD_LIBRARY_PATH variable correctly so you don't get missing library errors.
If you can't sign in to your Microsoft account, try opening the official Lunar Client launcher and signing in again. This is because the Launcher needs to be opened to sign in. After you sign in once, you should stay signed in.