Compiler crash with -Yrangepos ("Synthetic tree ... contains nonsynthetic tree"

[scabug]

Repro is here: https://github.com/ryan-williams/magic-rdds/tree/scalac-bug.

git clone
sbt ++2.10.6 clean compile

You'll see a compiler crash like this:

[error] uncaught exception during compilation: scala.tools.nsc.interactive.RangePositions$ValidateException
scala.tools.nsc.interactive.RangePositions$ValidateException: Synthetic tree [22450] contains nonsynthetic tree [22449]
	at scala.tools.nsc.interactive.RangePositions$class.positionError$1(RangePositions.scala:201)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:218)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
	at scala.tools.nsc.interactive.RangePositions$class.validate$1(RangePositions.scala:241)
…

More discussion can be found here.

[scabug]

Imported From: https://issues.scala-lang.org/browse/SI-10095?orig=1
Reporter: Ryan Williams (rdub)
Affected Versions: 2.10.6

[scabug]

@SethTisue said (edited on Jan 10, 2017 1:52:18 AM UTC):
presumably a duplicate of #8510, unless you can show it's reproducible in a recent 2.11.x or 2.12.x release