Use common settings in SBT `RootProject`

Question

The answer at https://stackoverflow.com/a/21605652/1737727 shows how to override one setting for a subproject defined with RootProject from the main project. I was

Answer 1

Well you could do this:

commonSettings.map { s => s.mapKey(Def.mapScope(_.in(util))) }

This creates new Seq[Setting[_]] where each of the setting's scopes is changed to be in the util project. This is a valid entry in an sbt file.

Another option is defining an sbt plugin that you add to both your main projects and in RootProject's own build.sbt

But you may want to consider if you actually need to import the util project as a RootProject instead of a regular subproject.