Multiple 'n' after exception takes to py IPython core, threading and logging library paths and results in TypeError

[dshivashankar1994]

Reproducer:

> cat a.py 
import time
a=1
while True:
    a += 1
    time.sleep(1)
    if a > 10:
       raise TimeoutError("FAILE")

> python  a.py &
[1] 128178

For debugger output, refer to the attached file

pyflyby output.txt

[aktech]

I tried to triage this last week, but seems like pyflyby's debugger requires gdb and gdb is not supported on M1 Macs.

(pyflyby)  $ python a.py &                                                                                                                                                                                          [0/269]
[1] 87930
(pyflyby)  $ py -d 87930
Traceback (most recent call last):
  File "/Users/aktech/miniconda3/envs/pyflyby/bin/py", line 33, in <module>
    sys.exit(load_entry_point('pyflyby', 'console_scripts', 'py')())
  File "/Users/aktech/quansight/pyflyby/lib/python/pyflyby/_py.py", line 2052, in py_main
    _PyMain(args).run()
  File "/Users/aktech/quansight/pyflyby/lib/python/pyflyby/_py.py", line 1787, in run
    self._run_action()
  File "/Users/aktech/quansight/pyflyby/lib/python/pyflyby/_py.py", line 1989, in _run_action
    attach_debugger(int(arg0, 10))
  File "/Users/aktech/quansight/pyflyby/lib/python/pyflyby/_dbg.py", line 1201, in attach_debugger
    gdb_pid = inject(pid, statements=";".join(statements), wait=False)
  File "/Users/aktech/quansight/pyflyby/lib/python/pyflyby/_dbg.py", line 1052, in inject
    process = subprocess.Popen(command,
  File "/Users/aktech/miniconda3/envs/pyflyby/lib/python3.8/subprocess.py", line 858, in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
  File "/Users/aktech/miniconda3/envs/pyflyby/lib/python3.8/subprocess.py", line 1704, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'gdb'

[aktech]

I tried reproducing on ubuntu 18.04, I get the following:

(pyflyby) $ python a.py &
[1] 119278
(pyflyby) $ py -d 119278
Traceback (most recent call last):
                                    File "/home/aktech/work/pyflyby/foo.py", line 7, in <module>
                                                                                                    raise TimeoutError("FAILE")
                                                                                                                               TimeoutError: FAILE
                                                                                                                                                  [1]  + 112745 exit 1     python foo.py

Debugging complete.
[1]+  Exit 1                  python a.py
(pyflyby) $

[aktech]

Tried with Ubuntu 22.04 as well, same result:

(venv) $ python a.py &
[1] 22701
(venv) $ py -d 22701
Traceback (most recent call last):
                                    File "/root/pyflyby/a.py", line 7, in <module>
                                                                                      raise TimeoutError("FAILE")
                                                                                                                 TimeoutError: FAILE

Debugging complete.
[1]+  Exit 1                  python a.py

GDB Version:

(venv) $ gdb --version
GNU gdb (Ubuntu 12.1-3ubuntu2) 12.1

[aktech]

@dshivashankar1994 Can you confirm you still see this issue in the latest master and with which OS/version and GDB version?

[sac111gp]

I tried it and was able to reproduce.
we are using 11.2 version of gdb.

$ gdb --version
GNU gdb (GDB) 11.2

[aktech]

I installed GDB 11.2 from here: https://sourceware.org/pub/gdb/releases/ and tried reproducing the issue, still the same results, I might be doing something wrong.

When I run the command py -d <PID>, pyflyby doesn't even takes me to the debugger, it just continues the execution, from what I can see.

cc @sac111gp @dshivashankar1994 I have written the exact commands/steps I used for reproduction, can you spot the difference?

Script

(venv) $ cat a.py
import time
a=1
while True:
    a += 1
    time.sleep(1)
    if a > 10:
       raise TimeoutError("FAILE")

Reproduction

(venv) $ python a.py &
[1] 68317
(venv) $ py -d 68317
Traceback (most recent call last):
                                    File "/root/pyflyby/a.py", line 7, in <module>
                                                                                      raise TimeoutError("FAILE")
                                                                                                                 TimeoutError: FAILE

Debugging complete.
[1]+  Exit 1                  python a.py

GDB Version

(venv) $ gdb --version
GNU gdb (GDB) 11.2
Copyright (C) 2022 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.

OS Version

(venv) $ cat /etc/*release
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=22.10
...

pyflyby version and latest commit

(venv) $ py --version
pyflyby 1.8.4 (py)

(venv) root@ubuntu-s-4vcpu-8gb-amd-fra1-01:~/pyflyby# git log -1
commit 238edc28fb00160f385ad5807cbb536b6417c866 (HEAD -> master, tag: 1.8.4, origin/master, origin/HEAD)
Author: Swapnil Ojha <[email protected]>
Date:   Mon Apr 17 21:22:34 2023 +0530

    Bump version 1.8.3 -> 1.8.4
(venv) root@ubuntu-s-4vcpu-8gb-amd-fra1-01:~/pyflyby#

[dshivashankar1994]

OS version

> cat /etc/*release
NAME="Red Hat Enterprise Linux Server"
VERSION="7.9 (Maipo)"

GDB version

> gdb --version
GNU gdb (GDB) 11.2

pyflyby version - Also reproducible with master version

> py --version
pyflyby 1.8.4 (py)

[aktech]

@dshivashankar1994 What terminal emulator are you using to test that and can you try another by any chance?

[Carreau]

@aktech
I had a few more success trying to attach to the python process and execute code manually to see the error messages.

First it seem my gdb is a bit stricter and I need to do some casting to make sure it works call (int)PyGILState_Ensure() (added (int)) and call (void)PyRun_SimpleString (added (void)).

Recent gdb should also let you run Python code with python subcommand, it might be easier to debug thigns by hand.

[aktech]

I had a few more success trying to attach to the python process and execute code manually to see the error messages.

Hey @Carreau can you share an example script of how that worked for you?

First it seem my gdb is a bit stricter and I need to do some casting to make sure it works call (int)PyGILState_Ensure() (added (int)) and call (void)PyRun_SimpleString (added (void)).

Did you wrote an extension or something?

[dshivashankar1994]

@dshivashankar1994 What terminal emulator are you using to test that and can you try another by any chance?

I was earlier using MATE terminal (xterm). Used GNOM (xterm) and the issue was still reproducible.
Same is the case with putty as well