type error of val in while condition

[Centaur]

Compiler version

3.0.0 , 3.0.1-RC1

Minimized code

  val c = List(1,2,3)
  var these = c
  while 
    val ne:Option[List[Int]] = Some(these.map(_+1))
    ne.get.nonEmpty
  do
    these = ne.map(_.tail).get

Output

value map is not a member of Object => Boolean

Expectation

should compile successfully

[bishabosha]

This is an example of shadowing of the pre-existing ne method on AnyRef, if we rename val ne to val newList then the error becomes more clear:

val c = List(1,2,3)
var these = c
while 
  val newList:Option[List[Int]] = Some(these.map(_+1))
  newList.get.nonEmpty
do
  these = newList.map(_.tail).get

we get the error:

7 |    these = newList.map(_.tail).get
  |            ^^^^^^^
  |            Not found: newList

This is because the definitions in the block of the condition of the while loop are not visible to the block in the do part

[som-snytt]

The misleading error was fixed in Scala 2 under scala/bug#5389

where ne is not due to wrapping object but member of Predef.

✗ scalac -d /tmp test/files/neg/t5389.scala
-- [E083] Type Error: test/files/neg/t5389.scala:2:7 ----------------------------------------------------------------------------
2 |import ne.scala
  |       ^^
  |       Object => Boolean is not a valid import prefix, since it is not an immutable path

Edit: forgot I'd created a ticket, pre-pandemic was a decade ago #7713