Question

I’m having trouble getting my new SBT task ‘install’ to depend on the OneJar task. Here’s my Build.scala file:

import sbt._
import Keys._
import com.github.retronym.SbtOneJar._

object BuildBroBuild extends Build {
  val install = TaskKey[Unit]("install", "Installs the JAR and a launcher script into your homedir")

  private def installTask = task {
    println("Hello world!")
  }

  override lazy val settings = super.settings ++
    Seq(install <<= (oneJar in Global)(installTask dependsOn(_)))

  lazy val root = Project(id = "buildbro",
                          base = file("."),
                          settings = Project.defaultSettings)
}

And here’s the error I’m getting:

[error] Reference to undefined setting: 
[error] 
[error]   */*:one-jar from {.}/*:install
[error]      Did you mean *:one-jar ?
[error]  

Does anybody know what this means? I believe I have to scope the oneJar TaskKey in a different way. Thanks for any help you can offer.

Answer 1

I think something like this should work:

object BuildBroBuild extends Build {
  val install = TaskKey[Unit]("install", "Installs the JAR and a launcher script into your homedir")

  private lazy val installTask = install <<= (oneJar, streams) map { case (a, s) => {
    // 'a' is the output from the onejar task (ie, the artifact)
    println("Hello world!")
  }

  override lazy val settings = super.settings ++
    Seq(installTask)

  lazy val root = Project(id = "buildbro",
                          base = file("."),
                          settings = Project.defaultSettings)
}

Here, we are taking the output of the oneJar task (as well as streams, which allows for logging, etc) as input for our new task.