pythongh-91960: Skip test_gdb if frame is <optimized out>

When Python is built with "clang -Og", gdb can fail to retrive the
'frame' parameter of _PyEval_EvalFrameDefault(). In this case, tests
like py_bt() are likely to fail. Without getting access to Python
frames, python-gdb.py is mostly clueless on retrieving the Python
traceback.

Lib/test/test_gdb.py

@@ -247,6 +247,9 @@ def get_stack_trace(self, source=None, script=None,
         for pattern in (
             '(frame information optimized out)',
             'Unable to read information on python frame',
+            # gh-91960: On Python built with "clang -Og", gdb gets
+            # "frame=<optimized out>" for _PyEval_EvalFrameDefault() parameter
+            '(unable to read python frame information)',
         ):
             if pattern in out:
                 raise unittest.SkipTest(f"{pattern!r} found in gdb output")

Misc/NEWS.d/next/Tests/2023-09-06-15-36-51.gh-issue-91960.P3nD5v.rst

@@ -0,0 +1,6 @@
+Skip ``test_gdb`` if gdb is unable to retrieve Python frame objects: if a
+frame is ``<optimized out>``. When Python is built with "clang -Og", gdb can
+fail to retrive the *frame* parameter of ``_PyEval_EvalFrameDefault()``. In
+this case, tests like ``py_bt()`` are likely to fail. Without getting access
+to Python frames, ``python-gdb.py`` is mostly clueless on retrieving the
+Python traceback.  Patch by Victor Stinner.