TypeError: '<=' not supported between instances of 'int' and 'NoneType'

[dima74]

Python 3.10, hanging_threads-2.0.5

Exception in thread Thread-1 (monitor):
Traceback (most recent call last):
  File "/usr/lib/python3.10/threading.py", line 1009, in _bootstrap_inner
    self.run()
  File "/usr/lib/python3.10/threading.py", line 946, in run
    self._target(*self._args, **self._kwargs)
  File "/home/dima/PycharmProjects/flats/venv/lib/python3.10/site-packages/hanging_threads.py", line 97, in monitor
    new_threads = get_current_frames()
  File "/home/dima/PycharmProjects/flats/venv/lib/python3.10/site-packages/hanging_threads.py", line 140, in get_current_frames
    return dict(
  File "/home/dima/PycharmProjects/flats/venv/lib/python3.10/site-packages/hanging_threads.py", line 142, in <genexpr>
    'frame': thread2list(frame),
  File "/home/dima/PycharmProjects/flats/venv/lib/python3.10/site-packages/hanging_threads.py", line 180, in thread2list
    l.insert(0, frame2string(frame))
  File "/home/dima/PycharmProjects/flats/venv/lib/python3.10/site-packages/hanging_threads.py", line 170, in frame2string
    line = linecache.getline(filename, lineno, frame.f_globals).lstrip()
  File "/usr/lib/python3.10/linecache.py", line 31, in getline
    if 1 <= lineno <= len(lines):
TypeError: '<=' not supported between instances of 'int' and 'NoneType'

[niccokunzmann]

Thanks for reporting!

[TheLizzard]

I believe that this happens when python code execution goes into C code in libraries - in my case pillow.

Adding if lineno is None: lineno = -1 in frame2string in hanging_threads.py should fix the problem. It doesn't raise an error as linecache just returns an empty string if the lineno is less than 1.

[niccokunzmann]

Thanks for looking into that. Would you like to create a pull request?