Forward declare invalid raises behaviour

forward_decl_and_raises.nim

type AnotherError = object of CatchableError

proc thisRaises() {.raises:[AnotherError].} # Works
#proc thisRaises() # Error: can raise an unlisted exception: Exception  - at line 8 :(

proc anotherProc() {.raises:[AnotherError].} =
  echo "Hoi"
  thisRaises()

proc thisRaises() {.raises:[AnotherError].} = # Whatever is put here doesn't seem to matter, can even omit.
  echo "Hi"
  raise newException(AnotherError, "oh no")

anotherProc()