Build the plugin from source

[RedIODev]

I'm trying to build the plugin from source but it fails on a compilation error.
What I'm doing:
run (sudo) ./gradlew build
What I expect:
getting a build extension I can load into vscode.
What I get:
build failure Task :gradle-server:compileJava:
error: package com.microsoft.java.bs.core does not exist
import com.microsoft.java.bs.core.Launcher;

I get that the build-server-for-gradle seems to be missing. But I have no Idea how to add it or load it as a dependency.