When I compile the following files with scalac
Scala compiler version 2.7.2.final -- Copyright 2002-2008, LAMP/EPFL
I get a StackOverflowError:

Exception in thread "main" java.lang.StackOverflowError
at scala.tools.nsc.Settings$$BooleanSetting.value(Settings.scala:343)
at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3305)
at scala.tools.nsc.typechecker.Typers$$Typer.typedQualifier(Typers.scala:
3380)
at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3240)
at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3323)
at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$typedApply$$1$$1.appl
y(Typers.scala:2607)
at scala.tools.nsc.typechecker.Typers$$Typer$$$$anonfun$$typedApply$$1$$1.appl
y(Typers.scala:2607)
at scala.tools.nsc.typechecker.Typers$$Typer.silent(Typers.scala:588)
at scala.tools.nsc.typechecker.Typers$$Typer.typedApply$$1(Typers.scala:26
07)
at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3219)
at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3323)
at scala.tools.nsc.typechecker.Typers$$Typer.typedQualifier(Typers.scala:
3380)
at scala.tools.nsc.typechecker.Typers$$Typer.typed1(Typers.scala:3240)
at scala.tools.nsc.typechecker.Typers$$Typer.typed(Typers.scala:3323)
...

In the past, I have been able to get around the problem by compiling files one by one. And sometimes by changing my path, I could get the problem to go away, but I'm not being able to avoid it this time. The problem is in the generated scanner (I've been
hacking JFlex to generate Scala so I could use it for my compiler class), but I haven't seen anything fishy in the Scala code.