Callbacks in methods cause internal error getTypeDescAux(tyBuiltInTypeClass)

[avahe-kellenberger]

Attempting to call a method on a "subclass" with a callback throws an internal error.

Example

type
  Entity = ref object of RootObj
  SubEntity = ref object of Entity
 
method foo(this: Entity, callback: proc = nil) {.base.} =
  if callback != nil:
    callback()

method foo(this: SubEntity, callback: proc = nil) =
  procCall Entity(this).foo(proc =
    echo "in callback"
  )
  
let sub = SubEntity()
sub.foo()

Current Output

From the playground:

usercode/in.nim(5, 1) Warning: generic methods are deprecated [Deprecated]
/usercode/in.nim(9, 1) Warning: generic methods are deprecated [Deprecated]
/usercode/in.nim(9, 8) Warning: use {.base.} for base methods; baseless methods are deprecated [UseBase]
Error: internal error: getTypeDescAux(tyBuiltInTypeClass)
No stack traceback available
To create a stacktrace, rerun compilation with './koch temp c <file>', see https://nim-lang.github.io/Nim/intern.html#debugging-the-compiler for details

Expected Output

in callback