I\'m developing a simple SBT project that includes InputTasks for benchmarking Scala Parallel collections.
I have defined the InputKeys and started writing the tasks
You can't modify the version of Scala that is used to to compile the project definition, because it must be a version binary compatible with the version used to compile SBT itself. There's some flexibility being studied in this regard, but, right now, it's fixed.
The setting scalaVersion
will change the version of Scala used to compile the project itself. The project can be compiled with completely different versions and, in fact, you can even have SBT compile your project with multiple Scala versions.