The version of lldb that comes with Xcode 9.2 will now work with SOS and the lldb plugin. We no longer have to build lldb locally.
The version of lldb that comes with Xcode 9.3/9.4 swift-4.1 will now work with SOS and the lldb plugin.
There has been no testing for the version of Xcode/lldb that comes with Mojave.