test_gdb fails under OS X 10.9.2 and gdb 7.6.1 (built with homebrew on Apple LLVM version 5.1 (clang-503.0.40)):

FAIL: test_pycfunction (test.test_gdb.PyBtTests)
Verify that "py-bt" displays invocations of PyCFunction instances
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/skimbrel/cpython/Lib/test/test_gdb.py", line 789, in test_pycfunction
    cmds_after_breakpoint=['bt', 'py-bt'],
  File "/Users/skimbrel/cpython/Lib/test/test_gdb.py", line 182, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ['No stack.', "Python Exception <class 'gd[109 chars]ed.'] != []

First list contains 3 additional elements.
First extra element 0:
No stack.

+ []
- ['No stack.',
-  "Python Exception <class 'gdb.error'> No frame is currently selected.: ",
-  'Error occurred in Python command: No frame is currently selected.']

======================================================================
FAIL: test_threads (test.test_gdb.PyBtTests)
Verify that "py-bt" indicates threads that are waiting for the GIL
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/skimbrel/cpython/Lib/test/test_gdb.py", line 736, in test_threads
    self.assertIn('Waiting for the GIL', gdb_output)
AssertionError: 'Waiting for the GIL' not found in 'Breakpoint 1 at 0x1001c78f0: file Python/bltinmodule.c, line 991.\n[New Thread 0x170b of process 41733]\n[New Thread 0x1803 of process 41733]\n[New Thread 0x1903 of process 41733]\n[New Thread 0x1a03 of process 41733]\n\nBreakpoint 1, builtin_id (self=<module at remote 0x100603358>, v=42) at Python/bltinmodule.c:991\n991\t    return PyLong_FromVoidPtr(v);\n\nThread 5 (Thread 0x1a03 of process 41733):\nTraceback (most recent call first):\n\nThread 4 (Thread 0x1903 of process 41733):\nTraceback (most recent call first):\n\nThread 3 (Thread 0x1803 of process 41733):\nTraceback (most recent call first):\n\nThread 2 (Thread 0x170b of process 41733):\nTraceback (most recent call first):\n\nThread 1 (Thread 0x1503 of process 41733):\nTraceback (most recent call first):\n  File "<string>", line 18, in <module>\n'

----------------------------------------------------------------------
Ran 45 tests in 19.277s

FAILED (failures=2)

Since Apple no longer ships gdb or GNU gcc as part of Xcode and since lldb is the native debugger for clang/LLVM, this test is usually skipped on OS X these days unless you go to the trouble of explicitly installing gdb.  Does anyone know if python support works when using gdb with clang?

See also duplicate Issue25992.  Unless someone has a better idea, I suggest we just disable test_gdb on OS X or, somewhat more precisely, when Python has been compiled with LLVM clang.

Hi ! I am willing to take a look into this. I am pretty new to the community and would appreciate some pointers relating to the issue which can give me a head-start to resolving it. 

Thanks in advance !

I am trying to create a PR for this and was thinking of somehow updating test.support, in order for someone to be able to find out what compiler was used to build python. Would that make sense?

Also, in case this is indeed something we'd like in test.support, what would be the correct sysconfig variables to read, in order to find that out?

New changeset 59668aa8b7f174b59304eab833c1c1181886c3c6 by Ned Deily (Lysandros Nikolaou) in branch 'master':
bpo-21263: Skip test_gdb when python has been compiled with LLVM clang (GH-10318)
https://github.com/python/cpython/commit/59668aa8b7f174b59304eab833c1c1181886c3c6

New changeset 96fb350bfd2c9b66d7804ae27ea8c4adbfabad5b by Ned Deily (Miss Islington (bot)) in branch '3.7':
bpo-21263: Skip test_gdb when python has been compiled with LLVM clang (GH-10318) (GH-10325)
https://github.com/python/cpython/commit/96fb350bfd2c9b66d7804ae27ea8c4adbfabad5b

New changeset f574ce79729ecb01f1f5b3e1a34c8aa7480b79e8 by Ned Deily (Miss Islington (bot)) in branch '3.6':
bpo-21263: Skip test_gdb when python has been compiled with LLVM clang (GH-10318) (GH-10326)
https://github.com/python/cpython/commit/f574ce79729ecb01f1f5b3e1a34c8aa7480b79e8

Thanks, everyone! Fixed for 3.8.0, 3.7.2, and 3.6.8.