Snapcraft issues with Alsa via pygame

Bala · April 26, 2024, 6:13am

Hello there, I am developing a simple application in python using pygame which plays sound files. here is my snapcraft.yaml

name: white-canary  # Replace with your application's name
base: core20             # The base snap is the execution environment
version: '0.8'                  # Version of your application
summary: A brief description of your application
description: A detailed description of your application.

grade: devel                    # Must be 'stable' to release into candidate/stable channels
confinement: strict             # Use 'strict' to enforce security and isolation

parts:
  white-canary:                     # This part name can be anything
    # Specifies where to fetch your source code from
    source: .                   # Use '.' to designate that the source code is in the same directory as the snapcraft.yaml
    plugin: python              # This plugin will use pip to install your Python packages
    python-packages:
      - flask                   # Ensure all your Flask dependencies are listed
      - pygame
      - requests
      - wheel
    stage-packages:             # List the Ubuntu packages needed at runtime
      - libasound2
      - alsa-utils
      - libasound2-plugins
      - libsdl1.2debian
      - libsdl-mixer1.2
      - libportaudio2
      - ffmpeg
      - libglu1-mesa
      - freeglut3

apps:
  white-canary:
    command: bin/hello     # Adjust to how you would run your app
    plugs:
      - network                 # Allows networking, e.g., access to the network
      - network-bind            # Allows binding to network ports
      - home                    # Grants access to non-hidden files in the user's home directory
      - audio-playback          # Allows playback of audio
      - audio-record            # Use if your application needs recording capabilities

The snap is building successfully, but when I run the app it fails with this error message

pygame 2.5.2 (SDL 2.28.2, Python 3.8.10)
Hello from the pygame community. https://www.pygame.org/contribute.html
ALSA lib conf.c:4120:(snd_config_update_r) Cannot access file /usr/share/alsa/alsa.conf
ALSA lib conf.c:4120:(snd_config_update_r) Cannot access file /usr/share/alsa/alsa.conf
ALSA lib pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM default
ALSA lib conf.c:4120:(snd_config_update_r) Cannot access file /usr/share/alsa/alsa.conf
ALSA lib conf.c:4120:(snd_config_update_r) Cannot access file /usr/share/alsa/alsa.conf
ALSA lib pcm.c:2642:(snd_pcm_open_noupdate) Unknown PCM default
Traceback (most recent call last):
  File "/snap/white-canary/x11/bin/hello", line 5, in <module>
    from src.app import main
  File "/snap/white-canary/x11/lib/python3.8/site-packages/src/app.py", line 12, in <module>
    pygame.mixer.init()
pygame.error: ALSA: Couldn't open audio device: No such file or directory

I tired connecting my snap to audio-playback, alsa manually, it didnt work
Also I noticed this warning message running the snapcraft command

Copying needed symlink target '/usr/bin/python3.8' from host to satisfy '/root/parts/white-canary/install/bin/python3'.
'lib/systemd/system/alsa-utils.service' will be a dangling symlink
Updating pull step for white-canary (source changed)
+ snapcraftctl pull
'lib/systemd/system/alsa-utils.service' will be a dangling symlink
Updating build step for white-canary ('pull' step changed)

Im running this on Intel PC 64 bit ubuntu desktop, when I normally run the python app, its working fine without any issues. Please help me with this, I wanted to do more with the snapcraft but this is blocking me. Thanks in Advance.

baldeuniversel · April 26, 2024, 10:02am

Hi @Bala .

Add this in your *.yaml file, and try again.

apps:
    white-canary:
        environment:
            LD_LIBRARY_PATH: $SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/pulseaudio:$LD_LIBRARY_PATH

popey · April 26, 2024, 10:03am

ALSA is a mess in snaps.

There’s a few ways to do it. @James-Carroll posted their solution a while back. Give that a try.

baldeuniversel · April 26, 2024, 10:15am

Do not hesitate to try this too :

Add this your python script .


import os
os.environ['SDL_AUDIODRIVER'] = 'dsp'
import pygame

popey · April 26, 2024, 10:26am

Why? What is the goal of this?

baldeuniversel · April 26, 2024, 10:35am

@popey , this variable allows to specify the audio driver that SDL (the library used by pygame to manage audio) should use.

By setting this environment variable, we might be able to work around some ALSA issues by telling SDL to use a different audio driver.

popey · April 26, 2024, 11:17am

Ok, but dsp is quite probably the worst option to choose, isn’t it?

baldeuniversel · April 26, 2024, 11:24am

@popey , pulse is also an alternative .

The dsp driver is the default audio driver for Unix systems.

popey · April 26, 2024, 11:27am

Ok, well let’s try and give people useful responses rather than random technology suggestions from 30 years ago, please.

baldeuniversel · April 26, 2024, 11:46am

Hmm ! @popey .

The goal in itself is that it works.

Afterwards we can vary according to our preferences.

No one is omniscient, I am here mainly to learn (in theory and in practice) .

popey · April 26, 2024, 12:53pm

Right, but I keep seeing what looks like either chat-gpt or random googling in responses to technical questions from you.

This leads people down the wrong path. If you have a solid answer which helps to resolve the question, then by all means answer the question. But if you pluck a random environment variable to select audio technology from the previous century, when we’ve all moved on from OSS through ALSA to Pulse and now Pipewire, the user is going to have a bad day. So please, can we try and post more researched and authoritative answers, not wild guesses?

baldeuniversel · April 26, 2024, 1:45pm

@popey ! One of the most desired wishes of a humain being aspiring to rational purity is to be perpetually in power.

As a French-speaking person, if I had thought that my words and writings should accurately reflect the depths of my thoughts and my soul, I would never express myself or write in English. However, I persevere in writing and speaking in English, because I am firmly convinced that it greatly contributes to my personal enrichment.

Not all answers may come from documented official sources or anything of that nature.
Moreover, there have never been any solutions that have become state-proven without rigorous testing. And yes, I sometimes use all the tools available that have proven their worth before making certain proposals or suggestions, and I am very happy about that.

Once again, I am mainly here to learn.

It often happens that we ignore our own initial learning here and there, especially when certain areas seem surprisingly familiar and easily masterable.

popey · April 26, 2024, 2:07pm

I didn’t ask for a philosophical diatribe. I asked you to provide actual technical support, not wild guesses.

Bala · April 26, 2024, 5:52pm

Hi @baldeuniversel thanks for the response,

I tried this along with dsp, I got this, if I ignore the dsp, Im facing the original issue, no difference.

pygame.error: dsp: No such audio device

also

CVE-2020-27348: A potentially empty LD_LIBRARY_PATH has been set for environment in 'white-canary'. The current working directory will be added to the library path if empty. This can cause unexpected libraries to be loaded.

Also got the above one while snapcraft

Bala · April 26, 2024, 6:02pm

Hi @popey, thank you for the response

I followed the solution posted by James, I added the alsa-pulseaudio to the parts and layout definition, following the github repo he posted.

this time it seems to find the alsa.conf but something else came up now,

Hello from the pygame community. https://www.pygame.org/contribute.html
ALSA lib control.c:1379:(snd_ctl_open_noupdate) Invalid CTL hw:0
ALSA lib dlmisc.c:283:(snd_dlobj_cache_get0) Cannot open shared library /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_pulse.so ((null): libpulsecommon-13.99.so: cannot open shared object file: No such file or directory)
ALSA lib control.c:1379:(snd_ctl_open_noupdate) Invalid CTL hw:0
ALSA lib control.c:1379:(snd_ctl_open_noupdate) Invalid CTL hw:0
ALSA lib dlmisc.c:283:(snd_dlobj_cache_get0) Cannot open shared library /usr/lib/x86_64-linux-gnu/alsa-lib/libasound_module_pcm_pulse.so ((null): libpulsecommon-13.99.so: cannot open shared object file: No such file or directory)
ALSA lib control.c:1379:(snd_ctl_open_noupdate) Invalid CTL hw:0
Traceback (most recent call last):
  File "/snap/white-canary/x20/bin/hello", line 5, in <module>
    from src.app import main
  File "/snap/white-canary/x20/lib/python3.8/site-packages/src/app.py", line 12, in <module>
    pygame.mixer.init()
pygame.error: ALSA: Couldn't open audio device: No such device or address

popey · April 26, 2024, 8:22pm

Could you please paste the entire snapcraft.yaml or a link to a git repo, so we can debug it?

Bala · April 26, 2024, 8:59pm

sure, here is the git repo white-canary

Thanks for taking your time to look in to this.

popey · April 26, 2024, 9:29pm

Thanks. I note you’re not staging libpulse0 as James does. Also James uses the gnome extension which takes away a few headaches

Bala · April 26, 2024, 9:51pm

After adding libpulse0 im still getting the same error. I am sorry if im wrong, but I thought gnome is related to UI, and I dont have any UI related stuff in my app. Regardless of that I added that too, and I got a new error.

RROR: Could not install packages due to an EnvironmentError: [Errno 30] Read-only file system: '__init__.py'

Failed to build 'white-canary'.

Recommended resolution:
Check the build logs and ensure the part's configuration and sources are correct.

without extension and adding libpulse0, Im getting the previous error, I posted.

Bala · April 30, 2024, 3:10am

@ogra @popey @baldeuniversel can you guys help me with this ?