gdb `py-bt` is no more compatible with Python 3.13+

[cielavenir]

Bug report

Bug description:

gdb ./python
r
Ctrl-C
py-bt

(gdb) py-bt
Traceback (most recent call first):
  (unable to read python frame information)

3.14.0b1 is affected and 3.14.0a7 is not affected.

Also I bisected git and found 1f5682f3a27516833f7c317707dd359280dba6e7. And reverting it onto 3.14.0 fixes py-bt:

(gdb) py-bt
Traceback (most recent call first):
  File "/home/user/devel/cpython/Lib/_pyrepl/unix_console.py", line 439, in wait
    or bool(self.pollob.poll(timeout))
  File "/home/user/devel/cpython/Lib/_pyrepl/reader.py", line 703, in handle1
    self.console.wait(100)
  File "/home/user/devel/cpython/Lib/_pyrepl/reader.py", line 748, in readline
    self.handle1()
  File "/home/user/devel/cpython/Lib/_pyrepl/readline.py", line 395, in multiline_input
    return reader.readline()
  File "/home/user/devel/cpython/Lib/_pyrepl/simple_interact.py", line 143, in run_multiline_interactive_console
    statement = multiline_input(more_lines, ps1, ps2)
  File "/home/user/devel/cpython/Lib/_pyrepl/main.py", line 58, in interactive_console
    run_multiline_interactive_console(console)

This can be confirmed by building https://github.com/cielavenir/cpython/commits/3.14.0-pybt .

However I don't know why "reenabling autovectorization" fixes py-bt.

There is a similar report https://github.com/python/cpython/issues/127147 but this issue happens without --enable-optimizations.

Tested on Debian 13, GCC 14

CPython versions tested on:

3.14

Operating systems tested on:

Linux

Linked PRs

• gh-142941
• gh-143371