As you can see in documentation SBT provides many ways to Configure and use Scala
Set the Scala version used for building the project
The scalaVersion configures the version of Scala used for compilation. By default, sbt also adds a dependency on the Scala library with this version. See the next section for how to disable this automatic dependency. If the Scala version is not specified, the version sbt was built against is used. It is recommended to explicitly specify the version of Scala.
For example, to set the Scala version to "2.9.2",
scalaVersion := "2.9.2"
Disable the automatic dependency on the Scala library
sbt adds a dependency on the Scala standard library by default. To disable this behavior, set the autoScalaLibrary setting to false.
autoScalaLibrary := false
Temporarily switch to a different Scala version
To set the Scala version in all scopes to a specific value, use the ++
command. For example, to temporarily use Scala 2.8.2, run:
> ++ 2.8.2
Use a local Scala installation for building a project
Defining the scalaHome setting with the path to the Scala home directory will use that Scala installation. sbt still requires scalaVersion to be set when a local Scala version is used. For example,
scalaVersion := "2.10.0-local"
scalaHome := Some(file("/path/to/scala/home/"))