freebsd/openbsd segfault in tests/lib-obj/test_reachable about ocaml-multicore HOT 1 CLOSED

CAMLprim value caml_obj_reachable_words(value v)
{
...
  extern_init_position_table(s);
...
  /* In Multicore OCaml, we don't distinguish between major heap blocks and
   * out-of-heap blocks, so we end up counting out-of-heap blocks too. */
  while (1) {
    if (Is_long(v)) {
      /* Tagged integers contribute 0 to the size, nothing to do */
    } else if (extern_lookup_position(s, v, &pos, &h)) {
 ...

static void extern_init_position_table(struct caml_extern_state* s)
{
  if (s->extern_flags & NO_SHARING) return;
  s->pos_table.size = POS_TABLE_INIT_SIZE;
  s->pos_table.shift = 8 * sizeof(value) - POS_TABLE_INIT_SIZE_LOG2;