test_gdb fails on Fedora 28. This happens only in debug build, and only if built with control flow protection flags: `-mcet -fcf-protection` AND optimization `-O0`.

Reproduction steps on Fedora 28 (x86_64):

./configure --with-pydebug
make 'EXTRA_CFLAGS=-mcet -fcf-protection -O0'
make test TESTOPTS='-v test_gdb'

Actual result:

Re-running test 'test_gdb' in verbose mode
GDB version 8.1:
    GNU gdb (GDB) Fedora 8.1-8.fc28
    Copyright (C) 2018 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
    This is free software: you are free to change and redistribute it.
    There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
    and "show warranty" for details.
    This GDB was configured as "x86_64-redhat-linux-gnu".
    Type "show configuration" for configuration details.
    For bug reporting instructions, please see:
    <http://www.gnu.org/software/gdb/bugs/>.
    Find the GDB manual and other documentation resources online at:
    <http://www.gnu.org/software/gdb/documentation/>.
    For help, type "help".
    Type "apropos word" to search for commands related to "word".
test_NULL_ob_type (test.test_gdb.PrettyPrintTests)
Ensure that a PyObject* with NULL ob_type is handled gracefully ... ok
test_NULL_ptr (test.test_gdb.PrettyPrintTests)
Ensure that a NULL PyObject* is handled gracefully ... ok
test_builtin_method (test.test_gdb.PrettyPrintTests) ... FAIL
test_builtins_help (test.test_gdb.PrettyPrintTests)
Ensure that the new-style class _Helper in site.py can be handled ... FAIL
test_bytes (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of bytes ... FAIL
test_corrupt_ob_type (test.test_gdb.PrettyPrintTests)
Ensure that a PyObject* with a corrupt ob_type is handled gracefully ... ok
test_corrupt_tp_flags (test.test_gdb.PrettyPrintTests)
Ensure that a PyObject* with a type with corrupt tp_flags is handled ... ok
test_corrupt_tp_name (test.test_gdb.PrettyPrintTests)
Ensure that a PyObject* with a type with corrupt tp_name is handled ... ok
test_dicts (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of dictionaries ... FAIL
test_exceptions (test.test_gdb.PrettyPrintTests) ... FAIL
test_frames (test.test_gdb.PrettyPrintTests) ... FAIL
test_frozensets (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of frozensets ... FAIL
test_getting_backtrace (test.test_gdb.PrettyPrintTests) ... ok
test_int (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of various int values ... FAIL
test_lists (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of lists ... FAIL
test_modern_class (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of new-style class instances ... FAIL
test_selfreferential_dict (test.test_gdb.PrettyPrintTests)
Ensure that a reference loop involving a dict doesn't lead proxyval ... FAIL
test_selfreferential_list (test.test_gdb.PrettyPrintTests)
Ensure that a reference loop involving a list doesn't lead proxyval ... FAIL
test_selfreferential_new_style_instance (test.test_gdb.PrettyPrintTests) ... FAIL
test_selfreferential_old_style_instance (test.test_gdb.PrettyPrintTests) ... FAIL
test_sets (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of sets ... FAIL
test_singletons (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of True, False and None ... FAIL
test_strings (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of unicode strings ... FAIL
test_subclassing_list (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of an instance of a list subclass ... FAIL
test_subclassing_tuple (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of an instance of a tuple subclass ... FAIL
test_truncation (test.test_gdb.PrettyPrintTests)
Verify that very long output is truncated ... FAIL
test_tuples (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of tuples ... FAIL
test_basic_command (test.test_gdb.PyListTests)
Verify that the "py-list" command works ... FAIL
test_one_abs_arg (test.test_gdb.PyListTests)
Verify the "py-list" command with one absolute argument ... FAIL
test_two_abs_args (test.test_gdb.PyListTests)
Verify the "py-list" command with two absolute arguments ... FAIL
test_down_at_bottom (test.test_gdb.StackNavigationTests)
Verify handling of "py-down" at the bottom of the stack ... FAIL
test_pyup_command (test.test_gdb.StackNavigationTests)
Verify that the "py-up" command works ... FAIL
test_up_at_top (test.test_gdb.StackNavigationTests)
Verify handling of "py-up" at the top of the stack ... FAIL
test_up_then_down (test.test_gdb.StackNavigationTests)
Verify "py-up" followed by "py-down" ... FAIL
test_bt (test.test_gdb.PyBtTests)
Verify that the "py-bt" command works ... FAIL
test_bt_full (test.test_gdb.PyBtTests)
Verify that the "py-bt-full" command works ... FAIL
test_gc (test.test_gdb.PyBtTests)
Verify that "py-bt" indicates if a thread is garbage-collecting ... ok
test_pycfunction (test.test_gdb.PyBtTests)
Verify that "py-bt" displays invocations of PyCFunction instances ... ok
test_threads (test.test_gdb.PyBtTests)
Verify that "py-bt" indicates threads that are waiting for the GIL ... ok
test_wrapper_call (test.test_gdb.PyBtTests) ... FAIL
test_basic_command (test.test_gdb.PyPrintTests)
Verify that the "py-print" command works ... FAIL
test_print_after_up (test.test_gdb.PyPrintTests) ... FAIL
test_printing_builtin (test.test_gdb.PyPrintTests) ... FAIL
test_printing_global (test.test_gdb.PyPrintTests) ... FAIL
test_basic_command (test.test_gdb.PyLocalsTests) ... FAIL
test_locals_after_up (test.test_gdb.PyLocalsTests) ... FAIL
======================================================================
FAIL: test_builtin_method (test.test_gdb.PrettyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 617, in test_builtin_method
    (gdb_repr, gdb_output))
AssertionError: None is not true : Unexpected gdb representation: '<unknown at remote 0x555555759c40>'
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<unknown at remote 0x555555759c40>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<unknown at remote 0x555555759c40>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_builtins_help (test.test_gdb.PrettyPrintTests)
Ensure that the new-style class _Helper in site.py can be handled
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 523, in test_builtins_help
    msg='Unexpected rendering %r' % gdb_repr)
AssertionError: None is not true : Unexpected rendering '<unknown at remote 0x7fffffffc7a8>'
======================================================================
FAIL: test_bytes (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of bytes
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 307, in test_bytes
    self.assertGdbRepr(b'')
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-in[326 chars]3b8>" != "b''"
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ b''
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected "b''"; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_dicts (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of dictionaries
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 295, in test_dicts
    self.assertGdbRepr({})
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-i[327 chars]3b8>" != '{}'
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ {}
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected '{}'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_exceptions (test.test_gdb.PrettyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 393, in test_exceptions
    ''')
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 241, in get_gdb_repr
    import_site=import_site)
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[197 chars]e: "] != []
First list contains 2 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xb0 in position 0: invalid start byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xb0 in position 0: invalid start byte: ',
-  "Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xb0 in position 0: invalid start byte: ']
======================================================================
FAIL: test_frames (test.test_gdb.PrettyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 627, in test_frames
    cmds_after_breakpoint=['print (PyFrameObject*)(((PyCodeObject*)v)->co_zombieframe)']
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ['Cannot access memory at address 0x90'] != []
First list contains 1 additional elements.
First extra element 0:
'Cannot access memory at address 0x90'
- ['Cannot access memory at address 0x90']
+ []
======================================================================
FAIL: test_frozensets (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of frozensets
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 379, in test_frozensets
    self.assertGdbRepr(frozenset(), "frozenset()")
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: '()' != 'frozenset()'
- ()
+ frozenset()
 : '()' did not equal expected 'frozenset()'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=()) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=()) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_int (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of various int values
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 281, in test_int
    self.assertGdbRepr(42)
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-i[327 chars]3b8>" != '42'
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ 42
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected '42'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_lists (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of lists
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 302, in test_lists
    self.assertGdbRepr([])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-i[327 chars]3b8>" != '[]'
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ []
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected '[]'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_modern_class (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of new-style class instances
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 418, in test_modern_class
    msg='Unexpected new-style class rendering %r' % gdb_repr)
AssertionError: None is not true : Unexpected new-style class rendering '<unknown at remote 0x7ffff7e47360>'
======================================================================
FAIL: test_selfreferential_dict (test.test_gdb.PrettyPrintTests)
Ensure that a reference loop involving a dict doesn't lead proxyval
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 542, in test_selfreferential_dict
    self.assertEqual(gdb_repr, "{'foo': {'bar': {...}}}")
AssertionError: "<CodecInfo(name='utf-8', encode=<built-in[326 chars]3b8>" != "{'foo': {'bar': {...}}}"
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ {'foo': {'bar': {...}}}
======================================================================
FAIL: test_selfreferential_list (test.test_gdb.PrettyPrintTests)
Ensure that a reference loop involving a list doesn't lead proxyval
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 530, in test_selfreferential_list
    self.assertEqual(gdb_repr, '[3, 4, 5, [...]]')
AssertionError: '<unknown at remote 0xf7e4a1a8>' != '[3, 4, 5, [...]]'
- <unknown at remote 0xf7e4a1a8>
+ [3, 4, 5, [...]]
======================================================================
FAIL: test_selfreferential_new_style_instance (test.test_gdb.PrettyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 568, in test_selfreferential_new_style_instance
    (gdb_repr, gdb_output))
AssertionError: None is not true : Unexpected gdb representation: '<unknown at remote 0x7ffff7e47360>'
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<unknown at remote 0x7ffff7e47360>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<unknown at remote 0x7ffff7e47360>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_selfreferential_old_style_instance (test.test_gdb.PrettyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 555, in test_selfreferential_old_style_instance
    (gdb_repr, gdb_output))
AssertionError: None is not true : Unexpected gdb representation: '<unknown at remote 0x7ffff7e47360>'
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<unknown at remote 0x7ffff7e47360>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<unknown at remote 0x7ffff7e47360>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_sets (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of sets
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 361, in test_sets
    self.assertGdbRepr(set(), "set()")
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: '()' != 'set()'
- ()
+ set()
 : '()' did not equal expected 'set()'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=()) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=()) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_singletons (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of True, False and None
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 289, in test_singletons
    self.assertGdbRepr(True)
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-i[327 chars]3b8>" != 'True'
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ True
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected 'True'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_strings (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of unicode strings
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 331, in test_strings
    self.assertGdbRepr('')
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-in[326 chars]3b8>" != "''"
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ ''
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected "''"; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_subclassing_list (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of an instance of a list subclass
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 432, in test_subclassing_list
    msg='Unexpected new-style class rendering %r' % gdb_repr)
AssertionError: None is not true : Unexpected new-style class rendering '<unknown at remote 0x7ffff7e475b8>'
======================================================================
FAIL: test_subclassing_tuple (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of an instance of a tuple subclass
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 447, in test_subclassing_tuple
    msg='Unexpected new-style class rendering %r' % gdb_repr)
AssertionError: None is not true : Unexpected new-style class rendering '<unknown at remote 0x7ffff7e47360>'
======================================================================
FAIL: test_truncation (test.test_gdb.PrettyPrintTests)
Verify that very long output is truncated
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 588, in test_truncation
    "[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, "
AssertionError: '<unknown at remote 0x7ffff7e395d0>' != '[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12[993 chars]ted)'
Diff is 1079 characters long. Set self.maxDiff to None to see it.
======================================================================
FAIL: test_tuples (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of tuples
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 353, in test_tuples
    self.assertGdbRepr(tuple(), '()')
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 277, in assertGdbRepr
    % (gdb_repr, exp_repr, gdb_output)))
AssertionError: "<CodecInfo(name='utf-8', encode=<built-i[327 chars]3b8>" != '()'
- <CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>
+ ()
 : "<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>" did not equal expected '()'; full output was:
Breakpoint 1 (builtin_id) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Breakpoint 1, builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
1120	{
#0  builtin_id (self=, v=<CodecInfo(name='utf-8', encode=<built-in method utf_8_encode of module object at remote 0x7ffff7e87ad8>, decode=<function at remote 0x7ffff7e19560>, incrementalencoder=<type at remote 0x5555557b26e8>, incrementaldecoder=<type at remote 0x5555557b2ae8>, streamwriter=<type at remote 0x5555557b2ee8>, streamreader=<type at remote 0x5555557b32e8>) at remote 0x7ffff7e7e3b8>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120
======================================================================
FAIL: test_basic_command (test.test_gdb.PyListTests)
Verify that the "py-list" command works
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 643, in test_basic_command
    cmds_after_breakpoint=['py-list'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_one_abs_arg (test.test_gdb.PyListTests)
Verify the "py-list" command with one absolute argument
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 658, in test_one_abs_arg
    cmds_after_breakpoint=['py-list 9'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_two_abs_args (test.test_gdb.PyListTests)
Verify the "py-list" command with two absolute arguments
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 669, in test_two_abs_args
    cmds_after_breakpoint=['py-list 1,3'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_down_at_bottom (test.test_gdb.StackNavigationTests)
Verify handling of "py-down" at the bottom of the stack
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 694, in test_down_at_bottom
    cmds_after_breakpoint=['py-down'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_pyup_command (test.test_gdb.StackNavigationTests)
Verify that the "py-up" command works
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 683, in test_pyup_command
    cmds_after_breakpoint=['py-up', 'py-up'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_up_at_top (test.test_gdb.StackNavigationTests)
Verify handling of "py-up" at the top of the stack
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 702, in test_up_at_top
    cmds_after_breakpoint=['py-up'] * 5)
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_up_then_down (test.test_gdb.StackNavigationTests)
Verify "py-up" followed by "py-down"
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 712, in test_up_then_down
    cmds_after_breakpoint=['py-up', 'py-up', 'py-down'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_bt (test.test_gdb.PyBtTests)
Verify that the "py-bt" command works
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 727, in test_bt
    cmds_after_breakpoint=['py-bt'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_bt_full (test.test_gdb.PyBtTests)
Verify that the "py-bt-full" command works
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 747, in test_bt_full
    cmds_after_breakpoint=['py-bt-full'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_wrapper_call (test.test_gdb.PyBtTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 866, in test_wrapper_call
    r"<method-wrapper u?'__init__' of MyList object at ")
AssertionError: Regex didn't match: "<method-wrapper u?'__init__' of MyList object at " not found in 'Breakpoint 1 (builtin_id) pending.\n[Thread debugging using libthread_db enabled]\nUsing host libthread_db library "/lib64/libthread_db.so.1".\n\nBreakpoint 1, builtin_id (self=, v=<unknown at remote 0xf7e4d238>) at /builddir/build/BUILD/Python-3.6.4/Python/bltinmodule.c:1120\n1120\t{\nBreakpoint 2: file /builddir/build/BUILD/Python-3.6.4/Objects/descrobject.c, line 1166.\n\nBreakpoint 2, wrapper_call (wp=<unknown at remote 0x7ffff7e71798>, args=0x0, kwds=<unknown at remote 0x7ffff77e8081>) at /builddir/build/BUILD/Python-3.6.4/Objects/descrobject.c:1166\n1166\t{\nTraceback (most recent call first):\n  <unknown at remote 0x7ffff7e71798>\n  File "<string>", line 4, in __init__\n  File "<string>", line 7, in <module>\n'
======================================================================
FAIL: test_basic_command (test.test_gdb.PyPrintTests)
Verify that the "py-print" command works
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 875, in test_basic_command
    cmds_after_breakpoint=['py-up', 'py-print args'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_print_after_up (test.test_gdb.PyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 884, in test_print_after_up
    cmds_after_breakpoint=['py-up', 'py-up', 'py-print c', 'py-print b', 'py-print a'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_printing_builtin (test.test_gdb.PyPrintTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 900, in test_printing_builtin
    cmds_after_breakpoint=['py-up', 'py-print len'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_printing_global (test.test_gdb.PyPrintTests)test test_gdb failed
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 892, in test_printing_global
    cmds_after_breakpoint=['py-up', 'py-print __name__'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_basic_command (test.test_gdb.PyLocalsTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 909, in test_basic_command
    cmds_after_breakpoint=['py-up', 'py-locals'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
======================================================================
FAIL: test_locals_after_up (test.test_gdb.PyLocalsTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 918, in test_locals_after_up
    cmds_after_breakpoint=['py-up', 'py-up', 'py-locals'])
  File "/builddir/build/BUILD/Python-3.6.4/Lib/test/test_gdb.py", line 219, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ["Python Exception <class 'UnicodeDecodeEr[82 chars]e: "] != []
First list contains 1 additional elements.
First extra element 0:
"Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode byte 0xf3 in position 0: invalid continuation byte: "
+ []
- ["Python Exception <class 'UnicodeDecodeError'> 'utf-8' codec can't decode "
-  'byte 0xf3 in position 0: invalid continuation byte: ']
----------------------------------------------------------------------
Ran 46 tests in 20.175s
FAILED (failures=37)
1 test failed again:
    test_gdb
Total duration: 29 min 42 sec
Tests result: FAILURE


Expected result: no failures

Original bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1541967

Ping. Could someone take a look? There is a PR ready.

New changeset 019d33b7a447e78057842332fb5d3bad01922122 by Victor Stinner in branch 'master':
bpo-32962: python-gdb catchs ValueError on read_var() (GH-7692)
https://github.com/python/cpython/commit/019d33b7a447e78057842332fb5d3bad01922122

Wouldn't be better to use the "surrogateescape" or the "backslashreplace" error handlers?

> Wouldn't be better to use the "surrogateescape" or the "backslashreplace" error handlers?

Are you talking about my https://github.com/python/cpython/pull/7693 fix? If yes, the error comes from the string() method which comes from the gdb API. I don't see how to control how gdb decodes bytes.

New changeset d22fc0bc7de7882da204abe50884bbde2da4f9e7 by Victor Stinner in branch 'master':
bpo-32962: python-gdb catchs UnicodeDecodeError (GH-7693)
https://github.com/python/cpython/commit/d22fc0bc7de7882da204abe50884bbde2da4f9e7

Reminder: test_gdb is skipped on Travis CI and AppVeyor. I tested my two changes manually. I will backport python-gdb.py enhancements to other branches once PR 6754 fix will be merged.

New changeset 9b7c74ca32d1bec7128d550a9ab1b2ddc7046287 by Victor Stinner (Marcel Plch) in branch 'master':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (#6754)
https://github.com/python/cpython/commit/9b7c74ca32d1bec7128d550a9ab1b2ddc7046287

New changeset ca4cb8492c643d1fcac2c5b749595ad5377673ab by Victor Stinner in branch '3.7':
[3.7] bpo-32962: Backport python-gdb.py and test_gdb.py from master (GH-7710)
https://github.com/python/cpython/commit/ca4cb8492c643d1fcac2c5b749595ad5377673ab

New changeset 5279759f52cc5397acfb04351b34feea862864de by Victor Stinner in branch '3.6':
bpo-32962: Backport python-gdb.py and test_gdb.py from master (GH-7710) (GH-7711)
https://github.com/python/cpython/commit/5279759f52cc5397acfb04351b34feea862864de

Oh :-( The change caused two buildbot failures, so I wrote PR 7723 to revert it.

x86 Gentoo Non-Debug with X 3.x:
http://buildbot.python.org/all/#/builders/99/builds/1095

======================================================================
FAIL: test_NULL_ptr (test.test_gdb.PrettyPrintTests)
Ensure that a NULL PyObject* is handled gracefully
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 481, in test_NULL_ptr
    'backtrace'])
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 239, in get_gdb_repr
    import_site=import_site)
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 217, in get_stack_trace
    self.assertEqual(unexpected_errlines, [])
AssertionError: Lists differ: ['No symbol "v" in current context.'] != []

First list contains 1 additional elements.
First extra element 0:
'No symbol "v" in current context.'

- ['No symbol "v" in current context.']
+ []

======================================================================
FAIL: test_builtins_help (test.test_gdb.PrettyPrintTests)
Ensure that the new-style class _Helper in site.py can be handled
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 517, in test_builtins_help
    gdb_repr, gdb_output = self.get_gdb_repr('id(__builtins__.help)', import_site=True)
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 246, in get_gdb_repr
    self.fail('Unexpected gdb output: %r\n%s' % (gdb_output, gdb_output))
AssertionError: Unexpected gdb output: 'Breakpoint 1 at 0xf1670: file Python/bltinmodule.c, line 1204.\n[Thread debugging using libthread_db enabled]\nUsing host libthread_db library "/lib/libthread_db.so.1".\n\nBreakpoint 1, builtin_id (self=, v=<_Helper at remote 0xb796c2ec>) at Python/bltinmodule.c:1204\n1204\t{\n__x86.get_pc_thunk.bx ()\n#0  __x86.get_pc_thunk.bx ()\n'
Breakpoint 1 at 0xf1670: file Python/bltinmodule.c, line 1204.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/libthread_db.so.1".

Breakpoint 1, builtin_id (self=, v=<_Helper at remote 0xb796c2ec>) at Python/bltinmodule.c:1204
1204	{
__x86.get_pc_thunk.bx ()
#0  __x86.get_pc_thunk.bx ()

======================================================================
FAIL: test_up_at_top (test.test_gdb.StackNavigationTests)
Verify handling of "py-up" at the top of the stack
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 702, in test_up_at_top
    'Unable to find an older python frame\n')
  File "/buildbot/buildarea/3.x.ware-gentoo-x86.nondebug/build/Lib/test/test_gdb.py", line 252, in assertEndsWith
    msg='%r did not end with %r' % (actual, exp_end))
AssertionError: False is not true : 'Breakpoint 1 at 0xf1670: file Python/bltinmodule.c, line 1204.\n[Thread debugging using libthread_db enabled]\nUsing host libthread_db library "/lib/libthread_db.so.1".\n\nBreakpoint 1, builtin_id (self=, v=42) at Python/bltinmodule.c:1204\n1204\t{\n__x86.get_pc_thunk.bx ()\nUnable to locate python frame\nUnable to locate python frame\nUnable to locate python frame\nUnable to locate python frame\nUnable to locate python frame\n' did not end with 'Unable to find an older python frame\n'



AMD64 Debian PGO 3.x:
http://buildbot.python.org/all/#/builders/47/builds/1173

======================================================================
FAIL: test_tuples (test.test_gdb.PrettyPrintTests)
Verify the pretty-printing of tuples
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/var/lib/buildbot/slaves/enable-optimizations-bot/3.x.gps-debian-profile-opt.nondebug/build/Lib/test/test_gdb.py", line 351, in test_tuples
    self.assertGdbRepr(tuple(), '()')
  File "/var/lib/buildbot/slaves/enable-optimizations-bot/3.x.gps-debian-profile-opt.nondebug/build/Lib/test/test_gdb.py", line 270, in assertGdbRepr
    gdb_repr, gdb_output = self.get_gdb_repr('id(' + ascii(val) + ')')
  File "/var/lib/buildbot/slaves/enable-optimizations-bot/3.x.gps-debian-profile-opt.nondebug/build/Lib/test/test_gdb.py", line 246, in get_gdb_repr
    self.fail('Unexpected gdb output: %r\n%s' % (gdb_output, gdb_output))
AssertionError: Unexpected gdb output: 'Breakpoint 1 at 0x16dc20: file Python/bltinmodule.c, line 1205.\n[Thread debugging using libthread_db enabled]\nUsing host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".\n\nBreakpoint 1, builtin_id (self=, v=()) at Python/bltinmodule.c:1205\n1205\t    return PyLong_FromVoidPtr(v);\nPyLong_FromVoidPtr () at Objects/longobject.c:1021\n1021\t{\n#0  PyLong_FromVoidPtr () at Objects/longobject.c:1021\n'
Breakpoint 1 at 0x16dc20: file Python/bltinmodule.c, line 1205.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".

Breakpoint 1, builtin_id (self=, v=()) at Python/bltinmodule.c:1205
1205	    return PyLong_FromVoidPtr(v);
PyLong_FromVoidPtr () at Objects/longobject.c:1021
1021	{
#0  PyLong_FromVoidPtr () at Objects/longobject.c:1021

> Oh :-( The change caused two buildbot failures, so I wrote PR 7723 to revert it.

It seems to only be related to this change:
"""
New changeset 9b7c74ca32d1bec7128d550a9ab1b2ddc7046287 by Victor Stinner (Marcel Plch) in branch 'master':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (#6754)
https://github.com/python/cpython/commit/9b7c74ca32d1bec7128d550a9ab1b2ddc7046287
"""

Since I also backported this change to 3.7 and 3.6, buildbot of 3.7 and 3.6 also failed:

AMD64 Debian PGO 3.7
http://buildbot.python.org/all/#builders/128/builds/417

AMD64 Debian PGO 3.6
http://buildbot.python.org/all/#builders/77/builds/419

x86 Gentoo Non-Debug with X 3.7
http://buildbot.python.org/all/#builders/115/builds/365

New changeset 2f9cbaa8b2190b6dfd3157ede9b6973523a3b939 by Victor Stinner in branch 'master':
Revert "bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-6754)" (#7723)
https://github.com/python/cpython/commit/2f9cbaa8b2190b6dfd3157ede9b6973523a3b939

New changeset 74565aa6d54344d4994c6b81d6fd05a4258283ab by Victor Stinner in branch '3.6':
Revert "bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-6754)" (#7725)
https://github.com/python/cpython/commit/74565aa6d54344d4994c6b81d6fd05a4258283ab

New changeset ba67b4f7cb87035e24098f52cf9711b9e793e033 by Victor Stinner in branch '3.7':
Revert "bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-6754)" (#7724)
https://github.com/python/cpython/commit/ba67b4f7cb87035e24098f52cf9711b9e793e033

New changeset e36f94f204f3257a206a7766464a94230337fd18 by Victor Stinner in branch '2.7':
bpo-32962: Backport python-gdb.py and test_gdb.py from master (GH-7726)
https://github.com/python/cpython/commit/e36f94f204f3257a206a7766464a94230337fd18

The problem is with this function:
static PyObject *
builtin_id(PyModuleDef *self, PyObject *v)
/*[clinic end generated code: output=0aa640785f697f65 input=5a534136419631f4]*/
{
    return PyLong_FromVoidPtr(v);
}

It's a one-liner, so the compiler really likes to inline it.

Without the inline optimization, the additional "next" command makes a jump into the function.

But when the function is inlined and you set a breakpoint to it, the line is just seen as a function from the debugger, that means you already are inside and the "next" makes the debugger exit this line, and so the function.

More graphical explanation:
non-inline case:
br
{
next
   return PyLong_FromVoidPtr(v);

inline case:
br
   return PyLong_FromVoidPtr(v);
next
"Some code without access to the func arguments' debug symbols"


I propose two possible solutions:
1) Skip whole test_gdb when optimizations are used (who debugs with them anyway?)
2) Conditionalize the "next". (this could be hard as we would need to know when the function is inlined)

Also, I have found out that when configured with --with-pydebug and --enable-optimizations, tests stop to fail. (the failing bots are configuring with --enable-optimizations only)

I'd say there are use cases where gdb will be used with optimizations especially in downstream distribution.

> 1) Skip whole test_gdb when optimizations are used (who debugs with them anyway?)

It's already done, no? But the title issue is "-mcet -fcf-protection
-O0" and -O0 disables optimizations.

Related issue: bpo-31237.

> It's already done, no? But the title issue is "-mcet -fcf-protection
> -O0" and -O0 disables optimizations.

Some of the simple tests are still run even with optimizations.
Disabled optimizations is what we want, because then the function doesn't get inlined --> the 'next' jumps in, not out.

Oh I see. But currently, many test_gdb tests pass even with optimization. I dislike reducing the test coverage when Python is compiled with optimizations, just to support -mcet -fcf-protection.

Would it be possible to detect the special case "-mcet -fcf-protection" *and* optimizations, and only skip test_gdb in that case?

More info about -fcf-protection=full -mcet:

"Enable control flow protection on x86-64 using -fcf-protection=full -mcet."
https://fedoraproject.org/wiki/Changes/HardeningFlags28

man gcc:

       -fcf-protection=[full|branch|return|none]
           Enable code instrumentation of control-flow transfers to increase
           program security by checking that target addresses of control-flow
           transfer instructions (such as indirect function call, function
           return, indirect jump) are valid.  This prevents diverting the flow
           of control to an unexpected target.  This is intended to protect
           against such threats as Return-oriented Programming (ROP), and
           similarly call/jmp-oriented programming (COP/JOP).

           The value "branch" tells the compiler to implement checking of
           validity of control-flow transfer at the point of indirect branch
           instructions, i.e. call/jmp instructions.  The value "return"
           implements checking of validity at the point of returning from a
           function.  The value "full" is an alias for specifying both
           "branch" and "return". The value "none" turns off instrumentation.

           The macro "__CET__" is defined when -fcf-protection is used.  The
           first bit of "__CET__" is set to 1 for the value "branch" and the
           second bit of "__CET__" is set to 1 for the "return".

           You can also use the "nocf_check" attribute to identify which
           functions and calls should be skipped from instrumentation.

           Currently the x86 GNU/Linux target provides an implementation based
           on Intel Control-flow Enforcement Technology (CET).

I tested the following configurations on my Fedora 28:

./configure --with-pydebug CFLAGS=-O0 -mcet -fcf-protection
./configure CFLAGS=-mcet -fcf-protection
./configure --with-pydebug CFLAGS=-O0 -mcet -fcf-protection=none
./configure CFLAGS=-mcet -fcf-protection=none
./configure --with-pydebug CFLAGS=-O0 -mcet -fcf-protection=branch
./configure CFLAGS=-mcet -fcf-protection=branch
./configure --with-pydebug CFLAGS=-O0 -mcet -fcf-protection=return
./configure CFLAGS=-mcet -fcf-protection=return
./configure --with-pydebug CFLAGS=-O0 -mcet -fcf-protection=full
./configure CFLAGS=-mcet -fcf-protection=full

test_gdb now pass with all these configurations

New changeset 79d21331e605fdc941f947621846b8563485aab6 by Victor Stinner in branch 'master':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-9656)
https://github.com/python/cpython/commit/79d21331e605fdc941f947621846b8563485aab6

New changeset 25bfb1aa75c8358becdab11142954c8ee9c3607f by Miss Islington (bot) in branch '3.6':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-9656)
https://github.com/python/cpython/commit/25bfb1aa75c8358becdab11142954c8ee9c3607f

New changeset 0ce31d340b264a550a3c574e1d6913f4affd4669 by Miss Islington (bot) in branch '3.7':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-9656)
https://github.com/python/cpython/commit/0ce31d340b264a550a3c574e1d6913f4affd4669

New changeset b274f1ce5c62dd517338b8323fb9eb5aaa09c7cd by Victor Stinner in branch '2.7':
bpo-32962: Fix test_gdb failure in debug build with -mcet -fcf-protection -O0 (GH-9656) (GH-9788)
https://github.com/python/cpython/commit/b274f1ce5c62dd517338b8323fb9eb5aaa09c7cd

Ok, the issue should now be fixed.

Thanks Iryna Shcherbina for your bug report, and thanks Marcel Plch for your initial fix! Marcel: my final fix is based on yours, I just made the "next" conditional.