My goal is to have a sbt jar file with all dependencies in order to create a debian package, so it could be install on machine without check/install package at first run. Is it the right choice use sbt-assembly to build a sbt jar with all dependencies?
The sbt binary version doesn't come with dependecies and sbt download them at first run.
I don't fully understand your use case, but would sbt-native-packager .deb format be a good fit?