Embedding Python crash on PyTuple_New

[Arnaud Loonstra]

Hi,

I've got Python embedded successfully in a program up until now as I'm 
now running into weird GC related segfaults. I'm currently trying to 
debug this but my understanding of CPython limits me here.

I'm creating a Tuple in C but it crashes on creating it after a while. 
It doesn't make sense which makes me wonder something else must be 
happening? Could be it just crashes here because the GC is cleaning up 
stuff completely unrelated to the allocation of the new tuple? How can I 
troubleshoot this?

I've got CPython compiled with  --with-valgrind --without-pymalloc 
--with-pydebug

In C I'm creating a tuple with the following method:

static PyObject *
s_py_zosc_tuple(pythonactor_t *self, zosc_t *oscmsg)
{
     assert(self);
     assert(oscmsg);
     char *format = zosc_format(oscmsg);

     PyObject *rettuple = PyTuple_New((Py_ssize_t) strlen(format) );

It segfaults here (frame 16) after 320 times (consistently) 


1   __GI_raise             raise.c          49   0x7ffff72c4e71
2   __GI_abort             abort.c          79   0x7ffff72ae536
3   fatal_error            pylifecycle.c    2183 0x7ffff7d84b4f
4   Py_FatalError          pylifecycle.c    2193 0x7ffff7d878b2
5   _PyObject_AssertFailed object.c         2200 0x7ffff7c93cf2
6   visit_decref           gcmodule.c       378  0x7ffff7dadfd5
7   tupletraverse          tupleobject.c    623  0x7ffff7ca3e81
8   subtract_refs          gcmodule.c       406  0x7ffff7dad340
9   collect                gcmodule.c       1054 0x7ffff7dae838
10  collect_with_callback  gcmodule.c       1240 0x7ffff7daf17b
11  collect_generations    gcmodule.c       1262 0x7ffff7daf3f6
12  _PyObject_GC_Alloc     gcmodule.c       1977 0x7ffff7daf4f2
13  _PyObject_GC_Malloc    gcmodule.c       1987 0x7ffff7dafebc
14  _PyObject_GC_NewVar    gcmodule.c       2016 0x7ffff7daffa5
15  PyTuple_New            tupleobject.c    118  0x7ffff7ca4da7
16  s_py_zosc_tuple        pythonactor.c    366  0x55555568cc82
17  pythonactor_socket     pythonactor.c    664  0x55555568dac7
18  pythonactor_handle_msg pythonactor.c    862  0x55555568e472
19  pythonactor_handler    pythonactor.c    828  0x55555568e2e2
20  sphactor_actor_run     sphactor_actor.c 855  0x5555558cb268
... <More>

Any pointer really appreciated.

Rg,

Arnaud