1. Local Scala

Local Scala 

To use a locally built Scala version, define the scalaHome setting, which is of type Option[File]. This Scala version will only be used for the build and not for sbt, which will still use the version it was compiled against.

Example:

scalaHome := Some(file("/path/to/scala"))

Using a local Scala version will override the scalaVersion setting and will not work with cross building.

sbt reuses the class loader for the local Scala version. If you recompile your local Scala version and you are using sbt interactively, run

> reload

to use the new compilation results.