More logs on the AArch64 issue.

It seems like *sometimes*, gdb fails to parse debug symbols of _testcapi.cpython-310d-aarch64-linux-gnu.so, whereas most of the time, "bt" shows symbols as expected.

stdout+stderr when the bug happens.

#######################################################
Function "meth_fastcall" not defined.
Breakpoint 1 (meth_fastcall) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
   1069559:	opening file=/home/vstinner/python/master/build/lib.linux-aarch64-3.10-pydebug/_testcapi.cpython-310d-aarch64-linux-gnu.so [0]; direct_opencount=1
   1069559:	

Program received signal SIGTRAP, Trace/breakpoint trap.
?? () from /home/vstinner/python/master/build/lib.linux-aarch64-3.10-pydebug/_testcapi.cpython-310d-aarch64-linux-gnu.so
#0  ?? () from /home/vstinner/python/master/build/lib.linux-aarch64-3.10-pydebug/_testcapi.cpython-310d-aarch64-linux-gnu.so
#1  ?? ()
Backtrace stopped: previous frame identical to this frame (corrupt stack?)
Unable to locate python frame
#######################################################

Extract of a successful run:
#######################################################
Function "meth_fastcall" not defined.
Breakpoint 1 (meth_fastcall) pending.
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".

Breakpoint 1, meth_fastcall (self=<module at remote 0xffffea683e90>, args=, nargs=0) at /home/vstinner/python/master/Modules/_testcapimodule.c:5255
5255	{
#0  meth_fastcall (self=<module at remote 0xffffea683e90>, args=, nargs=0) at /home/vstinner/python/master/Modules/_testcapimodule.c:5255
#1  cfunction_vectorcall_FASTCALL (func=<built-in method meth_fastcall of module object at remote 0xffffea683e90>, args=, nargsf=<optimized out>, kwnames=<optimized out>) at Objects/methodobject.c:424
#2  _PyObject_VectorcallTstate (tstate=, callable=<built-in method meth_fastcall of module object at remote 0xffffea683e90>, args=, nargsf=9223372036854775808, kwnames=0x0) at ./Include/cpython/abstract.h:114
#######################################################


I can reproduce the issue with command "./script.sh" using the following files.


script.sh:
---
$ cat script.sh 
OUT=$(mktemp)
while true; do
  gdb --batch -x cmds -args ./python -S x.py < /dev/null 2>&1 | tee $OUT 
  grep -q -F '<built-in method meth_fastcall' $OUT || break
  echo
  echo "===================================================="
  echo
done

echo "#######################################################"
echo "BUG!"
echo "#######################################################"
cat $OUT
echo "#######################################################"

rm -f $OUT
---


x.py:
---
import _testcapi
def foo():
#    _testcapi.meth_varargs()
    _testcapi.meth_fastcall()
def bar():
    foo()
bar()
---


cmds:
---
set breakpoint pending on
add-auto-load-safe-path /home/vstinner/python/master/python-gdb.py
set breakpoint pending yes
set print address off
break meth_fastcall
run
set print entry-values no
bt
py-bt
---