scalac assertion failed on compilable code: sym: Chunk$mcB$sp.bippy$mBc$sp target: Chunk.bippy #10018
Description
Scalac 2.12.0 got an assertion failure compiling the following code snippet.
It also affects 2.9 and 2.11.
The case is generated from an existing test program in the scala repository.
$ scalac -version
Scala compiler version 2.12.0-20161028-204919-0666377 -- Copyright 2002-2016, LAMP/EPFL and Lightbend, Inc.
$ scalac abc.scala
error: java.lang.AssertionError: assertion failed: sym: Chunk$mcB$sp.bippy$mBc$sp target: Chunk.bippy
at scala.tools.nsc.Global.assert(Global.scala:229)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.transformDefDef$1(SpecializeTypes.scala:1647)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.transform1(SpecializeTypes.scala:1721)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.$anonfun$transform$3(SpecializeTypes.scala:1461)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.reportError(SpecializeTypes.scala:1453)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.transform(SpecializeTypes.scala:1461)
at scala.tools.nsc.transform.SpecializeTypes$$anon$2.transform(SpecializeTypes.scala:1404)
<snipped>
$ cat abc.scala
trait Chunk[@specialized A] { def bippy[@specialized B >: A](e: B): Chunk[B] }