segmentation fault when starting test

[tedzards509]

ted@ted-laptop:~$ sudo howdy test

Opening a window with a test feed

Press ctrl+C in this terminal to quit
Click on the image to enable or disable slow mode

Segmentation fault

I had to manually configure my camera, however the face detection itself works with my config.

OS: Kubuntu
Kernel: 5.11.0-38-generic
Device: Lenovo ThinkPad E15 Gen 2 AMD

[boltgolt]

That sounds like an issue with opencv or dlib, could you try reinstalling those or reinstalling howdy?

[tedzards509]

I reinstalled opencv and ran pip3 opencv check which returned 'launchpadlib 1.10.13 requires testresources, which is not installed.` after reinstalling dlib there were no broken dependencies.

But even after intalling testresources the Segmentation fault persists.

[plafue]

I could narrow the problem down to opencv (segfaults when calling namedWindow).

I believe that the opencv version used by howdy (provided by the distribution, i suppose) is hit by this bug opencv/opencv-python#572 . This is the test i run on my Pop_OS installation (builds upon ubuntu 20.04):

≻  python3
Python 3.9.5 (default, May 11 2021, 08:20:37)
[GCC 10.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2 as cv
>>> cv.__version__
'4.5.4-dev'
>>> cv.__file__
'/usr/local/lib/python3.9/dist-packages/cv2/__init__.py'
>>> cv.namedWindow("test")
[1]    23573 segmentation fault (core dumped)  python3

When installing a newer version of opencv via pip and running the same commands as above, namedWindow does not segfault anymore.

≻  pip install --force-reinstall opencv-python==4.5.4.60
Defaulting to user installation because normal site-packages is not writeable
Collecting opencv-python==4.5.4.60
  Using cached opencv_python-4.5.4.60-cp39-cp39-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (60.3 MB)
Collecting numpy>=1.19.3
  Using cached numpy-1.21.4-cp39-cp39-manylinux_2_12_x86_64.manylinux2010_x86_64.whl (15.7 MB)
Installing collected packages: numpy, opencv-python
  Attempting uninstall: numpy
    Found existing installation: numpy 1.21.4
    Uninstalling numpy-1.21.4:
      Successfully uninstalled numpy-1.21.4
  Attempting uninstall: opencv-python
    Found existing installation: opencv-python 4.5.4.60
    Uninstalling opencv-python-4.5.4.60:
      Successfully uninstalled opencv-python-4.5.4.60
Successfully installed numpy-1.21.4 opencv-python-4.5.4.60
≻  python3
Python 3.9.5 (default, May 11 2021, 08:20:37)
[GCC 10.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv2 as cv
>>> cv.__version__
'4.5.4'
>>> cv.__file__
'/home/plafue/.local/lib/python3.9/site-packages/cv2/__init__.py'
>>> cv.namedWindow("test")
# window appears, no segfault

I frankly don't know where /usr/local/lib/python3.9/dist-packages/cv2/__init__.py comes from or how is it installed (maybe i installed manually in the past? when installing other software?) - but it being a -dev version seems to be problematic. The seemingly related package python3-opencv is not defined as a dependency on the howdy deb package (i'm not that familiar with the python ecosystem and find all the packaging/dependency resolution confusing).

I forced installing the newer version system-wide (probably strongly not recommended, but YOLO - it is a bugfix version bump) via sudo pip install --force-reinstall opencv-python==4.5.4.60 and now howdy test works.

[boltgolt]

Thanks for figuring that out @plafue!

[tedzards509]

It works now so I guess this can be marked as closed. Thanks plafue.