pygame.display.init fails if not started by root on Raspberry Pi

[Vinalti]

Environment:

You can get some of this info from the text that pops up in the console when you run a pygame program.

• Operating system : RaspberryPi OS - No XServer - Light version
• Python version: 3.7.3
• SDL version : 2.x.x ?
• PyGame version : 1.9.4.post1
• Relevant hardware : Raspberry Pi 4 - Connected to a LCD HDMI Screen

Current behavior:
When user runs display.init() an error happens : pygame.error: Unable to open a console terminal

import pygame
pygame.display.init()
# pygame.error: Unable to open a console terminal

If run as root, everything is working.

Expected behavior:
If user as proper persmission display.init should work

Steps to reproduce:
On a raspberrypi without XServer, connect an HDMI screen, install pygame.

import pygame
pygame.display.init()

Error message:
pygame.error: Unable to open a console terminal

Stack trace/error output/other error logs

pygame.error: Unable to open a console terminal

No stacktrace

QUESTION

What permissions is needed to have display.init() working as non-root user ?

More details : https://stackoverflow.com/q/70757953/17965313

Notes

• Setting environment variable SDL_VIDEODRIVER to fbcon or dummy is not solving the issue
• Root can do a display.init() without problem
• There are no XServer running so DISPLAY is not set and doesn't exist.
• I need to do a dispay.init() however I don't need a display.

[ankith26]

Hi! First of all, pygame 1.9.4 is a rather dated version of pygame, perhaps you should upgrade to pygame 2.1.2 (fair warning, pygame2 has issues on pi hardware ATM, so this will likely be slower than pygame 1.9.4)
I'm not really sure, but I believe the videodriver should be set to fbcon in your case. If you used sudo while setting the environment variable, it is invisible to processes run without sudo. So remember to set the environment variable without sudo

[Vinalti]

Hello @ankith26, thank you for your answer, I tried setting up the SDL_VIDEODRIVER environment variable (directly in the python code with os.environ[...] = ... ) but it doesn't help. Also I don't need to do this to make it work as root, so I think it is a permission issue. Nevertheless I couldn't find which file would it be.
Version 1.9.4 is working fine (is the default when using apt install python3-pygame) and I have the same issue nevertheless with the version 2.1.2 (installed with pip install pygame ).

[robertpfeiffer]

Which version of Raspberry Pi OS are you on? With the latest version of PyGame and Pi OS, I would not recommend fbcon (but that would be correct for PyGame 1.9.4) but KMS/DRM. https://wiki.libsdl.org/FAQUsingSDL

[robertpfeiffer]

It feels like there is some vital context missing here