ScriptEngine under sbt doesn't load/run

[scabug]

This version of the test at #8521 fails to find ScriptEngine under sbt.

Created directly, the compiler fails to initialize.

import javax.script._
import scala.tools.nsc.interpreter._

object Main extends App {

  val ngine = new ScriptEngineManager().getEngineByName("scala").asInstanceOf[ScriptEngine with Compilable]
  val iMain = ngine.asInstanceOf[Scripted].intp

  //val ngine = new Scripted.Factory().getScriptEngine.asInstanceOf[ScriptEngine with Compilable]
  //val iMain = ngine.asInstanceOf[Scripted].intp

  class Foo
  iMain.settings.embeddedDefaults[Foo]

  println(Thread.currentThread().getContextClassLoader)
  ngine.compile("val x = 1")
  println(Thread.currentThread().getContextClassLoader)
}

[info] Running checkcl.Main 
[error] (run-main-0) scala.reflect.internal.FatalError: class StringContext does not have a member f
scala.reflect.internal.FatalError: class StringContext does not have a member f
	at scala.reflect.internal.Definitions$DefinitionsClass.fatalMissingSymbol(Definitions.scala:1239)
	at scala.reflect.internal.Definitions$DefinitionsClass.$anonfun$getMember$1(Definitions.scala:1262)
	at scala.reflect.internal.Definitions$DefinitionsClass.getMember(Definitions.scala:1257)
	at scala.reflect.internal.Definitions$DefinitionsClass.getMemberMethod(Definitions.scala:1291)
	at scala.reflect.internal.Definitions$DefinitionsClass$RunDefinitions.StringContext_f$lzycompute(Definitions.scala:1478)
	at scala.reflect.internal.Definitions$DefinitionsClass$RunDefinitions.StringContext_f(Definitions.scala:1478)
	at scala.tools.reflect.FastTrack.$anonfun$fastTrackCache$1(FastTrack.scala:53)
	at scala.reflect.internal.SymbolTable$perRunCaches$$anon$1.apply(SymbolTable.scala:395)
	at scala.tools.reflect.FastTrack.contains(FastTrack.scala:20)
	at scala.tools.nsc.typechecker.Namers$Namer.methodSig(Namers.scala:1294)
[snip]
	at scala.tools.nsc.typechecker.Typers$Typer.typed(Typers.scala:5555)
	at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.apply(Analyzer.scala:102)
	at scala.tools.nsc.Global$GlobalPhase.$anonfun$applyPhase$1(Global.scala:402)
	at scala.tools.nsc.Global$GlobalPhase.applyPhase(Global.scala:395)
	at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.$anonfun$run$1(Analyzer.scala:94)
	at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.$anonfun$run$1$adapted(Analyzer.scala:93)
	at scala.collection.AbstractIterator.foreach(Iterator.scala:932)
	at scala.tools.nsc.typechecker.Analyzer$typerFactory$$anon$3.run(Analyzer.scala:93)
	at scala.tools.nsc.Global$Run.compileUnitsInternal(Global.scala:1404)
	at scala.tools.nsc.Global$Run.compileUnits(Global.scala:1389)
	at scala.tools.nsc.Global$Run.compileSources(Global.scala:1384)
	at scala.tools.nsc.interpreter.IMain._initialize(IMain.scala:129)
	at scala.tools.nsc.interpreter.IMain.initializeSynchronous(IMain.scala:149)
	at scala.tools.nsc.interpreter.Scripted.<init>(Scripted.scala:74)
	at scala.tools.nsc.interpreter.Scripted$.apply(Scripted.scala:309)
	at scala.tools.nsc.interpreter.Scripted$Factory.getScriptEngine(Scripted.scala:302)

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-10058?orig=1
Reporter: @som-snytt
Affected Versions: 2.12.0
See #8521

[tyrcho]

This issue could be related : https://stackoverflow.com/questions/44217163/dynamic-compilation-with-scala-2-12-from-sbt-test (same stack trace, same goal to compile dynamically from sbt)

[scf37]

Root of the problem is that sbt for reason unknown runs tests with java system property java.class.path set to ...bin/sbt-launch.jar

I managed to make scala compiler work by using -javacp and passing different classpath collected from sbt:

sbtClasspath := {
      val cp = (fullClasspath in Test).value.map(x => x.data.getAbsolutePath).mkString(":")
      System.setProperty("sbt-classpath", cp)
}

This approach works up to Scala 2.12.4. 2.12.5 and up still fail with abovementioned exception.