Refinement with concrete type and method throw RecursionOverflow:

[steinybot]

Compiler version

3.3.0-RC3

Minimized code

type Y = { type T = String; def u(): T }

trait Test {

  val y1: Y
  val y2 = y1.u()
}

Output

Recursion limit exceeded.
Maybe there is an illegal cyclic reference?
If that's not the case, you could also try to increase the stacksize using the -Xss JVM option.
For the unprocessed stack trace, compile with -Yno-decode-stacktraces.
A recurring operation is (inner to outer):

  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  ...

  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member Object#T
  find-member y1.u

Expectation

I'm would expect this one to compile.

It is pretty strange. It triggers when:

• The refinement has a concrete type member.
• There is a method that has a parameter list (even if empty) and the return type is the type member

This is similar to #17380 although it appears to be quite different but perhaps it is the same underlying bug. This one throws at the call site.