I've also seen a crash in lru_cache_tp_traverse but with the 3.5.0b3 release build for the OS X 64-bit/32-bit installer.  I just stumbled across the segfault by bringing up the interactive interpreter and typing "import ssl".  After a lot of playing around, I reduced the failing case to: 1. have an "import pprint" in a startup file referred to by PYTHONSTARTUP *and* 2. "import ssl" must be the very first command entered in the interactive interpreter. Odd!  Unfortunately, the release build is a non-debug build and, so far, I have not been able to reproduce the segfault with any other build, debug or non-debug.  So, whatever the problem is, it's very build dependent.  Here is the OS X system traceback from the segfault:  

Path:                  /Library/Frameworks/Python.framework/Versions/3.5.0b3_10_6/Resources/Python.app/Contents/MacOS/Python
Identifier:            Python
Version:               ???
Code Type:             X86-64 (Native)
Parent Process:        bash [51285]
Responsible:           iTerm [754]
User ID:               503

Date/Time:             2015-07-10 19:57:16.086 -0700
OS Version:            Mac OS X 10.10.4 (14E46)
Report Version:        11
Anonymous UUID:        CFED52E3-698C-835B-D61C-F4B1F18D2CB6


Time Awake Since Boot: 800000 seconds

Crashed Thread:        0  Dispatch queue: com.apple.main-thread

Exception Type:        EXC_BAD_ACCESS (SIGSEGV)
Exception Codes:       KERN_INVALID_ADDRESS at 0x0000000000000018

VM Regions Near 0x18:
--> 
    __TEXT                 0000000100000000-0000000100001000 [    4K] r-x/rwx SM=COW  /Library/Frameworks/Python.framework/Versions/3.5.0b3_10_6/Resources/Python.app/Contents/MacOS/Python

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   org.python.python             	0x000000010015e5e5 lru_cache_tp_traverse + 37
1   org.python.python             	0x000000010013a2d7 collect + 439
2   org.python.python             	0x000000010013aee5 _PyObject_GC_Alloc + 357
3   org.python.python             	0x000000010013afe7 _PyObject_GC_New + 23
4   org.python.python             	0x0000000100059bce PyDict_New + 334
5   org.python.python             	0x000000010015f029 lru_cache_new + 249
6   org.python.python             	0x00000001000795a6 type_call + 38
7   org.python.python             	0x000000010000dc93 PyObject_Call + 99
8   org.python.python             	0x00000001000e9fd8 PyEval_EvalFrameEx + 7656
9   org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
10  org.python.python             	0x00000001000f035d PyEval_EvalFrameEx + 33133
11  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
12  org.python.python             	0x00000001000f1e07 PyEval_EvalCodeEx + 71
13  org.python.python             	0x00000001000e5ff5 builtin___build_class__ + 485
14  org.python.python             	0x0000000100065549 PyCFunction_Call + 281
15  org.python.python             	0x00000001000f0768 PyEval_EvalFrameEx + 34168
16  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
17  org.python.python             	0x00000001000f1e61 PyEval_EvalCode + 81
18  org.python.python             	0x00000001000e5683 builtin_exec + 627
19  org.python.python             	0x0000000100065519 PyCFunction_Call + 233
20  org.python.python             	0x00000001000f0a9b PyEval_EvalFrameEx + 34987
21  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
22  org.python.python             	0x00000001000f035d PyEval_EvalFrameEx + 33133
23  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
24  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
25  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
26  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
27  org.python.python             	0x00000001000f1e07 PyEval_EvalCodeEx + 71
28  org.python.python             	0x000000010004017a function_call + 186
29  org.python.python             	0x000000010000dc93 PyObject_Call + 99
30  org.python.python             	0x0000000100010ff6 _PyObject_CallMethodIdObjArgs + 454
31  org.python.python             	0x000000010010d6d3 PyImport_ImportModuleLevelObject + 1171
32  org.python.python             	0x00000001000e5e03 builtin___import__ + 131
33  org.python.python             	0x0000000100065549 PyCFunction_Call + 281
34  org.python.python             	0x000000010000dc93 PyObject_Call + 99
35  org.python.python             	0x00000001000e64f7 PyEval_CallObjectWithKeywords + 87
36  org.python.python             	0x00000001000ea43e PyEval_EvalFrameEx + 8782
37  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
38  org.python.python             	0x00000001000f1e61 PyEval_EvalCode + 81
39  org.python.python             	0x00000001000e5683 builtin_exec + 627
40  org.python.python             	0x0000000100065519 PyCFunction_Call + 233
41  org.python.python             	0x00000001000f0a9b PyEval_EvalFrameEx + 34987
42  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
43  org.python.python             	0x00000001000f035d PyEval_EvalFrameEx + 33133
44  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
45  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
46  org.python.python             	0x00000001000f07fd PyEval_EvalFrameEx + 34317
47  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
48  org.python.python             	0x00000001000f1e07 PyEval_EvalCodeEx + 71
49  org.python.python             	0x000000010004017a function_call + 186
50  org.python.python             	0x000000010000dc93 PyObject_Call + 99
51  org.python.python             	0x0000000100010ff6 _PyObject_CallMethodIdObjArgs + 454
52  org.python.python             	0x000000010010d6d3 PyImport_ImportModuleLevelObject + 1171
53  org.python.python             	0x00000001000e5e03 builtin___import__ + 131
54  org.python.python             	0x0000000100065549 PyCFunction_Call + 281
55  org.python.python             	0x000000010000dc93 PyObject_Call + 99
56  org.python.python             	0x00000001000e64f7 PyEval_CallObjectWithKeywords + 87
57  org.python.python             	0x00000001000ea43e PyEval_EvalFrameEx + 8782
58  org.python.python             	0x00000001000f1d00 _PyEval_EvalCodeWithName + 2400
59  org.python.python             	0x00000001000f1e61 PyEval_EvalCode + 81
60  org.python.python             	0x000000010011fa7a PyRun_InteractiveOneObject + 474
61  org.python.python             	0x000000010011fdfe PyRun_InteractiveLoopFlags + 110
62  org.python.python             	0x000000010012076c PyRun_AnyFileExFlags + 76
63  org.python.python             	0x00000001001390a9 Py_Main + 3785
64  org.python.python             	0x0000000100000e32 0x100000000 + 3634
65  org.python.python             	0x0000000100000c84 0x100000000 + 3204

Thread 0 crashed with X86 Thread State (64-bit):
  rax: 0x000000010023d6c0  rbx: 0x00000001006fdb70  rcx: 0x0000000100382048  rdx: 0x0000000000000000
  rdi: 0x0000000000000000  rsi: 0x00000001001392e0  rbp: 0x00007fff5bffb530  rsp: 0x00007fff5bffb510
   r8: 0x0000000000000000   r9: 0x0000000000000001  r10: 0x0000000000000016  r11: 0x00000001001392e0
  r12: 0x00000001006fdb88  r13: 0x0000000000000000  r14: 0x00000001001392e0  r15: 0x000000010102fdb8
  rip: 0x000000010015e5e5  rfl: 0x0000000000010206  cr2: 0x0000000000000018