Compiler stackoverflow for recursive implicit materializer

[scabug]

Given the following implicit materializer:

package show

import scala.reflect.macros.blackbox
import scala.language.experimental.macros

trait Show[T] {
  def show(t: T) : String
}

object Show {
    implicit def materializeShow[T] : Show[T] = macro materializeShowImpl[T]

    def materializeShowImpl[T: c.WeakTypeTag](c : blackbox.Context) : c.Tree = {
        import c.universe._
        val tag: WeakTypeTag[T] = implicitly[WeakTypeTag[T]]
        val tpe = tag.tpe

        val caseAttributes = tpe.members.collect {
            case m: MethodSymbol if m.isCaseAccessor => m
        }.toList

        val implicits = caseAttributes.map { ca =>
            q"implicitly[_root_.show.Show[${ca.typeSignature.resultType}]].show(t.$ca)"
        }

        q"""
            new _root_.show.Show[$tpe] {
              def show(t: $tpe) : String = {
                List(..$implicits).mkString(",")
              }
            }
        """
    }
}

Compiling the following code

case class A( b : B )
case class B( a : A )

implicitly[Show[A]]

will throw a Stackoverflow

Error:scalac: Error: org.jetbrains.jps.incremental.scala.remote.ServerException
java.lang.StackOverflowError
	at scala.tools.nsc.typechecker.Contexts$Context.nextOuter(Contexts.scala:619)
	at scala.tools.nsc.typechecker.Contexts$Context.implicitss(Contexts.scala:857)
	at scala.tools.nsc.typechecker.Contexts$Context.withOuter$1(Contexts.scala:859)
	at scala.tools.nsc.typechecker.Contexts$Context.implicitss(Contexts.scala:880)
	at scala.tools.nsc.typechecker.Contexts$Context.withOuter$1(Contexts.scala:859)

Is this related to SI-8141?

Update

Although this isn't straightforward there is a workaround as described in there : scalamacros/macrology201@012db5c

    val name = TermName(c.freshName())
    q"""
          implicit object $name extends _root_.show.Show[$tpe] {
            [...]
          }
          $name
       """

I believe it would be less error prone if the macro system would detect this situation and either:

1. fail comprehensibly by suggesting the workaround
2. automatically turn anonymous class into an implicit object

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-9048?orig=1
Reporter: Bruno Bieth (mustaghattack)
Affected Versions: 2.11.4