Python2: py-bt frame information optimized out

On system python2 on Debian 11 bullseye, when you try py-bt on gdb, session, frames are optimized out:

(gdb) py-bt
Traceback (most recent call first):
  (frame information optimized out)

According to https://www.podoliaka.org/2016/04/10/debugging-cpython-gdb/ , this is because gdb wasn't able to figure out the location of PyFrameObject data structure in a given stack frame.

So, to fix this, you can rebuild python2 without PGO.

• https://salsa.debian.org/cpython-team/python2/-/merge_requests/7
• https://github.com/cielavenir/salsa-python2/releases/tag/2.7.18-13.0.1

Note that system Python 3.9 does not have issue.