SBT BuildInfo example 2 - output in /src

file1.scala

object BuildInfo {

  private def outputDir(baseDir: File): File = baseDir / "src_mananaged"

  lazy val settings: Seq[Setting[_]] = Seq(
    managedSourceDirectories in Compile <+= baseDirectory apply {baseDir => outputDir(baseDir)},
    sourceGenerators in Compile <+= (streams, baseDirectory, version) map emitBuildInfo
  )

  def emitBuildInfo(logger: TaskStreams, baseDir: File, buildVersion: String): Seq[File] = {
    val outputFile = outputDir(baseDir) / "BuildInfo.scala"
    logger.log.info(s"Generating build info file at: ${outputFile}")
    IO.delete(outputFile)
    IO.write(outputFile,
      s"""
         |package buildInfo
         |
         |object BuildInfo {
         | val version = "$buildVersion"
         |}""".stripMargin)
    Seq(outputFile)
  }
}