sbt 0.13.16 - How do I println(systemProperty) in build.sbt file?

Question

I am migrating a Build.scala file to a build.sbt file.

In the Build.scala file, there are print statements that print out vals (of type String) defined in the body of the Build.scala file.

project/Build.scala:

import sbt._
import Keys._

object HelloBuild extends Build {
    val foo = System.getProperty("foo")
    println(foo)
}

How do I migrate these print statements to the build.sbt file?

Answer 1

You can't just print it. You are declaring your build, but when it will be printed is different story. Probably it should be within a task for instance. From docs:

myTask := {
  val log = streams.value.log
  val propertyFoo = System.getProperty("foo")
  log.info(s"property foo = $propertyFoo")
}