value tailLabel does not take parameters

[olafurpg]

Trying to compile scalastyle with dotty at commit: matthewfarwell/scalastyle@92b81e0

I get the compiler error:

error: value tailLabel624 does not take parameters

Running with -Ycheck:all and -Ycheck:firstTransform I get the following error:

[trace] Stack trace suppressed: run last compile:compileIncremental for the full output.
[error] (compile:compileIncremental) java.lang.AssertionError: assertion failed: error at /Users/ollie/dev/scalastyle/src/main/scala/org/scalastyle/Checker.scala:184
[error] type mismatch:
[error]  found   : Array[Class[_]]
[error]  required: Class[_]
[error] tree = Typed(JavaSeqLiteral(List(), TypeTree[RefinedType(TypeRef(ThisType(TypeRef(NoPrefix,lang)),Class), java$lang$Class$$T, TypeBounds(TypeRef(ThisType(TypeRef(NoPrefix,scala)),Nothing), TypeRef(ThisType(TypeRef(NoPrefix,scala)),Any)))]),TypeTree[RefinedType(TypeRef(ThisType(TypeRef(NoPrefix,scala)),Array), scala$Array$$T, TypeAlias(RefinedType(TypeRef(ThisType(TypeRef(NoPrefix,lang)),Class), java$lang$Class$$T, TypeBounds(TypeRef(ThisType(TypeRef(NoPrefix,scala)),Nothing), TypeRef(ThisType(TypeRef(NoPrefix,scala)),Any))), 0))])

linking to this line in Checker.scala:

      val c: Checker[_] = clazz.getConstructor().newInstance().asInstanceOf[Checker[_]]

Removing the block containing that line I get the original "taillabel does not take parameters" error instead of "type mismatch" when compiled with -Ycheck:all.

Any hints on how to better debug this?

[matthewfarwell]

This is a minimized example, which fails in dotr:

object Foobar {
  def apply(): Option[String] = { 
    def foobar[A](f: (String, String) => A): List[A] = List[String]() match { 
      case _ :: ls => foobar(f) 
    } 
    foobar((a1, a2) => (a1 + a2)).headOption 
  } 
}

[DarkDimius]

@matthewfarwell, was able to reproduce. Thank you!