StackOverflow in TypeApplications

[nicolasstucki]

i4371b.scala (#4371) has been spuriously failing with a stack overflow

object App {
  type T[G[X] <: X, F[X] <: G[F[X]]]
}

[nicolasstucki]

This failed in

• http://dotty-ci.epfl.ch/lampepfl/dotty/10322/4
• http://dotty-ci.epfl.ch/lampepfl/dotty/10325/4
• http://dotty-ci.epfl.ch/lampepfl/dotty/10327/4

[abgruszecki]

AFAIR this was related to runtime state of JVM and therefore difficult to reproduce - we just sometimes hit the stack limit. @nicolasstucki do we want to care about this, or do we want to close the issue?

[smarter]

You could try to reproduce by reducing the stack size used by the JVM (-Xss)

[liufengyun]

Now the compiler reports:

-- Error: examples/i5860.scala:2:25 --------------------------------------------
2 |  type T[G[X] <: X, F[X] <: G[F[X]]]
  |                         ^
  |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.
  |A recurring operation is (inner to outer):
  |
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of LazyRef(F[X])
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of LazyRef(F[X])
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of LazyRef(F[X])
  |  type parameters of G[LazyRef(F[X])]
  |  ...
  |
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of LazyRef(F[X])
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of LazyRef(F[X])
  |  type parameters of G[LazyRef(F[X])]
  |  type parameters of F[X]
  |  type parameters of G[F[X]]
  |  type parameters of  <: G[F[X]]
one error found