Destructors don't work on objects allocated by new :(

destest.nim

type
  TThing = object
    a: int
  PThing = ref TThing

proc destruct1(instance: var TThing) {.destructor.} =
  echo "destory TThing number ", instance.a

block:
  var a: TThing = TThing(a: 2)
  # prints "destory TThing number 2"

var a: PThing
new(a)
a.a = 3
a = nil
# should print now "destroy TThing number 3"