I had the same problem with D. As an example of what I feel stack traces should look like, compare it to the stack traces that Nim gives.

  ~/temp_code » ./greetings
  Traceback (most recent call last)
  greetings.nim(9)        greetings
  greetings.nim(6)        hola
  SIGSEGV: Illegal storage access. (Attempt to read from nil?)

For the code:

  type
    Greetings = ref object
      name: string

  proc hola(g: Greetings) =
    echo g.name

  var g: Greetings
  g.hola()