Sonar-slang - missing class

I am compiling the sonar-slang v.1.8.0 from source, intending to run with 7.9 LTS, using “gradlew build”. The compile completes without issue,. However all four of the plugins refuse to load with an “Caused by: java.lang.NoClassDefFoundError: org/sonarsource/slang/plugin/SlangSensor” error. There aren’t any instructions on how to package sonar-slang so maybe I’m missing a file, or there is a file I need to install outside of the extensions directory?

(While I am here, what do I do with the three sonar-go-to-slang executables? I copied them into the extensions directory, but I’m not getting far enough along to see if that works)