Segmentation fault with simple example

[DanielSSilva]

Hi! Let me start by stating that I'm not super familiar with Python and I'm new to using this library. I'm using this library to develop a project with the NeoPixels. I've followed the installation guide and I'm able to get the expected results, however, everytime the program finishes I have a segmentation fault.
From what I was able to understand, this library uses the ws_281x C library, which can be where the problem relies....

Type of Raspberry Pi

Tested on a Rpi3 and Zero W

Linux Kernel version

Linux raspberrypi 5.10.17-v7+ #1414 SMP Fri Apr 30 13:18:35 BST 2021 armv7l GNU/Linux

Expected behaviour

Code run without any issue

Actual behaviour

Message is successfully displayed on the LEDs, but after that I get Segmentation fault, without any further information.

Here's the sample that I'm using

from luma.led_matrix.device import neopixel
from luma.core.legacy import show_message
from luma.core.legacy.font import proportional, SPECCY_FONT #https://luma-core.readthedocs.io/en/latest/_modules/luma/core/legacy/font.html

device = neopixel(width=16, height=7)
device.contrast(50)
def main():
    msg = "Hi!"
    show_message(device, msg, y_offset=-1, fill="green", font=proportional(SPECCY_FONT), scroll_delay=0.04)    

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        pass

[thijstriemstra]

after that I get Segmentation fault, without any further information.

Can you paste at least the seg fault message? And what python 3 version are you using? can you try a different version?

[DanielSSilva]

Can you paste at least the seg fault message?

That's the thing, the only message that I get is "Segmentation fault". There's no stack trace or anything related.

And what python 3 version are you using? can you try a different version?

I've just installed raspbian, so I'm assuming it's either 3.6 or 3.7. I'll try with another version when I get the chance. Should I try with some 3.x, or should it be with 2.x?

[thijstriemstra]

Only 3.x is supported. Check version with python --version or python3 --version.

[DanielSSilva]

Here's both the python3 version (3.7.3) as well as the segmentation fault message that I get.
What's the best way to test with other python version? I was googling and seemed to be through pyenv? What's the recommended way to achieve this?

[thijstriemstra]

We have seen more issues with the stock version of Python on Raspbian. If you try latest Python 3.7.x I'm pretty sure the segfault will be gone. Unfortunately I don't see an quick way to upgrade Python on Raspbian, only compile from source.

It should be pretty straightforward though, download .zip file, unpack it and

./configure
make -j4
sudo make install
/usr/local/bin/python3 --version

And then reinstall luma.led_matrix with that new Python version.

[thijstriemstra]

was googling and seemed to be through pyenv?

ps. i dont use pyenv but it might work as well.

[thijstriemstra]

If you try latest Python 3.7.x I'm pretty sure the segfault will be gone.

No feedback, closing.