Error importing scala.tools.reflect.ToolBox in SBT - scala

Question

I am trying to compile the following code in SBT as part of a subproject.
package bitstream.compiler
package eval
import scala.reflect.runtime.universe._
import scala.reflect.runtime.currentMirror
import scala.tools.reflect.ToolBox
// Based on code from:
// https://gist.github.com/xuwei-k/9ba39fe22f120cb098f4
object Eval {
def apply[A](tree: Tree): A = {
val toolbox = currentMirror.mkToolBox()
toolbox.eval(tree).asInstanceOf[A]
}
}
Here is my build.sbt:
lazy val commonSettings = Seq(
organization := "com.bitbucket.example-project",
scalaVersion := "2.12.6"
)
lazy val root = (project in file("."))
.settings(
commonSettings,
version := "0.1.0-SNAPSHOT",
name := "example-project"
)
lazy val plugin = (project in file("plugin"))
.settings(
commonSettings,
scalacOptions += "-J-Xss256m",
name := "plugin",
libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value
)
.dependsOn(root)
libraryDependencies += "org.scalatest" %% "scalatest" % "3.0.5" % Test
libraryDependencies += "org.scala-lang" % "scala-reflect" % scalaVersion.value
I try to compile the plugin subproject using plugin/package, and I get the error object tools is not a member of package scala. As far as I know, scala.tools should be provided by the scala-compiler dependency. Is there something I am missing?

Answer 1

scala.tools.reflect.ToolBox is in scala-compiler.jar. Try libraryDependencies += "org.scala-lang" % "scala-compiler" % scalaVersion.value. Sbt does not assume that you will use classes in scala-compiler.jar directly. - this is documented in https://www.scala-sbt.org/1.0/docs/Configuring-Scala.html