I managed to get a core dump locally. Interestingly, it may be that the _tk module is the culprit. The backtrace is the following:

#0  0x00007ff6c5e14aab in raise () from /lib/x86_64-linux-gnu/libpthread.so.0
#1  0x000000000044e57e in faulthandler_fatal_error (signum=11) at ./Modules/faulthandler.c:305
#2  <signal handler called>
#3  0x00000000004c085e in _Py_Dealloc (op=<unknown at remote 0x7ff6bca2ac20>) at Objects/object.c:1873
#4  0x00000000004a8085 in free_keys_object (keys=0x3100ab0) at Objects/dictobject.c:378
#5  0x00000000004ab0e8 in dict_dealloc (mp=0x7ff6be6194b8) at Objects/dictobject.c:1400
#6  0x00000000004c0860 in _Py_Dealloc (
    op={'children': <unknown at remote 0x7ff6bc9ab3d8>, 'master': None, 'tk': <unknown at remote 0x7ff6bca2ac20>, '_tkloaded': 1, '_tclCommands': None}) at Objects/object.c:1873
#7  0x00000000004d7ac7 in subtype_dealloc (
    self=<Tk(children=<unknown at remote 0x7ff6bc9ab3d8>, master=None, tk=<unknown at remote 0x7ff6bca2ac20>, _tkloaded=1, _tclCommands=None) at remote 0x7ff6bc9a7dc0>) at Objects/typeobject.c:1049
#8  0x00000000004c0860 in _Py_Dealloc (
    op=<Tk(children=<unknown at remote 0x7ff6bc9ab3d8>, master=None, tk=<unknown at remote 0x7ff6bca2ac20>, _tkloaded=1, _tclCommands=None) at remote 0x7ff6bc9a7dc0>) at Objects/object.c:1873
#9  0x00000000004a8085 in free_keys_object (keys=0x3100e40) at Objects/dictobject.c:378
#10 0x00000000004aac8f in PyDict_Clear (op={}) at Objects/dictobject.c:1291
#11 0x00000000004dd9c8 in type_clear (type=0x14f45b8) at Objects/typeobject.c:2981
#12 0x000000000043a703 in delete_garbage (collectable=0x7fffab364300, old=0x8de7c0 <generations+64>) at Modules/gcmodule.c:854
#13 0x000000000043ac9d in collect (generation=2, n_collected=0x0, n_uncollectable=0x0, nofail=1) at Modules/gcmodule.c:1020
#14 0x000000000043bfa3 in _PyGC_CollectNoFail () at Modules/gcmodule.c:1619
#15 0x00000000005c6cb6 in PyImport_Cleanup () at Python/import.c:420
#16 0x000000000041d992 in Py_Finalize () at Python/pythonrun.c:552
#17 0x000000000042392b in Py_Exit (sts=0) at Python/pythonrun.c:2474
#18 0x000000000042114b in handle_system_exit () at Python/pythonrun.c:1673
#19 0x0000000000421176 in PyErr_PrintEx (set_sys_last_vars=1) at Python/pythonrun.c:1683
#20 0x0000000000420ddd in PyErr_Print () at Python/pythonrun.c:1590
#21 0x0000000000437fc4 in RunModule (modname=0xf4d570 L"test", set_argv0=1) at Modules/main.c:227
#22 0x0000000000439279 in Py_Main (argc=18, argv=0xf4c020) at Modules/main.c:715
#23 0x00000000004199b5 in main (argc=18, argv=0x7fffab364908) at ./Modules/python.c:69