String interpolation doesn't work well with implicits

[scabug]

String interpolation when used with implicits throws weird runtime exception.

Example code:

object Test extends App {

  implicit def CustomPattern(ctx: StringContext) = new {
    object pattern {
      def unapplySeq(s: String): Option[Seq[String]] = Some(Seq())
    }
  }

  println("" match { case pattern"" => "yay!" })
} 

Runtime error:

java.lang.IllegalAccessError: tried to access field sandbox.CustomPatternTest$.reflParams$Cache1 from class sandbox.CustomPatternTest$delayedInit$body
	at sandbox.CustomPatternTest$delayedInit$body.<clinit>(Test.scala:11)
	at sandbox.CustomPatternTest$.<init>(Test.scala:3)
	at sandbox.CustomPatternTest$.<clinit>(Test.scala)
	at sandbox.CustomPatternTest.main(Test.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at scala.tools.nsc.util.ScalaClassLoader$$anonfun$run$1.apply(ScalaClassLoader.scala:71)
	at scala.tools.nsc.util.ScalaClassLoader$class.asContext(ScalaClassLoader.scala:31)
	at scala.tools.nsc.util.ScalaClassLoader$URLClassLoader.asContext(ScalaClassLoader.scala:139)
	at scala.tools.nsc.util.ScalaClassLoader$class.run(ScalaClassLoader.scala:71)
	at scala.tools.nsc.util.ScalaClassLoader$URLClassLoader.run(ScalaClassLoader.scala:139)
	at scala.tools.nsc.CommonRunner$class.run(ObjectRunner.scala:28)
	at scala.tools.nsc.ObjectRunner$.run(ObjectRunner.scala:45)
	at scala.tools.nsc.CommonRunner$class.runAndCatch(ObjectRunner.scala:35)
	at scala.tools.nsc.ObjectRunner$.runAndCatch(ObjectRunner.scala:45)
	at scala.tools.nsc.MainGenericRunner.runTarget$1(MainGenericRunner.scala:74)
	at scala.tools.nsc.MainGenericRunner.process(MainGenericRunner.scala:96)
	at scala.tools.nsc.MainGenericRunner$.main(MainGenericRunner.scala:105)
	at scala.tools.nsc.MainGenericRunner.main(MainGenericRunner.scala)

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-6382?orig=1
Reporter: @densh
Affected Versions: 2.10.0-M7

[scabug]

@paulp said:
It has nothing to do with string interpolation or implicits; it is a bug in delayedinit, and a duplicate of #5565. Use a main method instead of "extends App" and it works.