No sound on certain Linux distros

[iacore]

🐞 Bug report 🐞

Description

alda play has no sound. No new audio source in Pulseaudio.

Steps to Reproduce

1. alda -v2 play -c "piano: c12 e g > c4"

Does the problem happen consistently?
Yes

Expected Behavior

It should make some sound, at least.

Actual Behavior

alda doctor says everything is fine.

Environment

Operating system and version: Linux

Alda version:

$ alda version
alda 2.2.5

$ alda-player info
alda-player 2.2.5
log path: /home/user/.cache/alda/logs

Health check:

$ alda doctor
(all ok)

Logs:

qqw INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/players...
qqw INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/repl-servers...
qqw INFO  2023-10-20 06:09:28 Main.run:77 - Starting receiver, listening on port 37537...
fgx INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/players...
qqw INFO  2023-10-20 06:09:28 MidiEngine.<init>:276 - Initializing MIDI sequencer...
fgx INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/repl-servers...
qqw INFO  2023-10-20 06:09:28 MidiEngine.<init>:281 - Initializing MIDI synthesizer...
fgx INFO  2023-10-20 06:09:28 Main.run:77 - Starting receiver, listening on port 45865...
zbx INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/players...
zbx INFO  2023-10-20 06:09:28 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/repl-servers...
zbx INFO  2023-10-20 06:09:28 Main.run:77 - Starting receiver, listening on port 40081...
fgx INFO  2023-10-20 06:09:28 MidiEngine.<init>:276 - Initializing MIDI sequencer...
fgx INFO  2023-10-20 06:09:28 MidiEngine.<init>:281 - Initializing MIDI synthesizer...
zbx INFO  2023-10-20 06:09:28 MidiEngine.<init>:276 - Initializing MIDI sequencer...
zbx INFO  2023-10-20 06:09:28 MidiEngine.<init>:281 - Initializing MIDI synthesizer...
qqw INFO  2023-10-20 06:09:31 Main.run:90 - Starting player...
fgx INFO  2023-10-20 06:09:31 Main.run:90 - Starting player...
zbx INFO  2023-10-20 06:09:31 Main.run:90 - Starting player...
qqw INFO  2023-10-20 06:09:42 Main.invoke:95 - Stopping receiver...
qqw INFO  2023-10-20 06:09:42 Main.invoke:97 - Stopping player...
xnu INFO  2023-10-20 06:12:20 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/players...
xnu INFO  2023-10-20 06:12:20 StateManager.cleanUpStaleStateFiles:72 - Cleaning up stale files in /home/user/.cache/alda/state/repl-servers...
xnu INFO  2023-10-20 06:12:20 Main.run:77 - Starting receiver, listening on port 38459...
xnu INFO  2023-10-20 06:12:20 MidiEngine.<init>:276 - Initializing MIDI sequencer...
xnu INFO  2023-10-20 06:12:20 MidiEngine.<init>:281 - Initializing MIDI synthesizer...
xnu INFO  2023-10-20 06:12:22 Main.run:90 - Starting player...

[daveyarwood]

Hi @iacore , thanks for reporting this. Unfortunately, I don't have any strong theories about what might be the cause of the issue. Everything in the logs you posted looks normal, and the alda doctor checks passing would suggest that it's not an issue with the player processes starting or the MIDI system failing to start, etc.

My best guess is that this is some kind of Pulseaudio-related issue. Just as a point of reference, I have been using Alda for years with no issues on my Ubuntu laptops (16.04, 20.04, 22.04) with Pulseaudio.

Out of curiosity, what Linux distro are you using?

[daveyarwood]

And as a sanity check: is audio working for you, in general? For example, can you hear YouTube videos?

[iacore]

My Linux distro is Artix.

Every other application has sound.

I found a workaround to the problem

alda-player run -p 27278
ALDA_DISABLE_SPAWNING=yes alda -v 2 play -p 27278 -c 'piano: c e g'

[daveyarwood]

Very interesting! So it seems like maybe sound isn't being produced when the processes are spawned in the background, but it works when the process is running in the foreground 🤔

[iacore]

Now the workaround doesn't work...

[UlyssesZh]

Same symptom. Using foreground alda-player does not fix this either. Distro is NixOS 24.05.

[daveyarwood]

@iacore @UlyssesZh Happy New Year! I've just released a new version of Alda (2.4.1) that includes debug-level logging when the player process starts, showing what audio devices are detected and which one was chosen.

After updating Alda, to see this new output, you can run a player process in the foreground with alda-player -v run. You should see debug logs like this:

...
vmj INFO  2026-01-01 19:22:14 Main.run:77 - Starting receiver, listening on port 27701...
vmj INFO  2026-01-01 19:22:14 MidiEngine.info:261 - [0] Initializing MIDI sequencer...
vmj DEBUG 2026-01-01 19:22:14 MidiEngine.logAudioMixers:171 - Detected audio mixers:
vmj DEBUG 2026-01-01 19:22:14 MidiEngine.logAudioMixers:174 - Mixer: name='Port Generic [hw:0]', vendor='ALSA (http://www.alsa-project.org)', version='6.8.0-90-generic', description='HD-Audio Generic, ATI R6xx HDMI'
vmj DEBUG 2026-01-01 19:22:14 MidiEngine.logAudioMixers:174 - Mixer: name='Port Generic_1 [hw:1]', vendor='ALSA (http://www.alsa-project.org)', version='6.8.0-90-generic', description='HD-Audio Generic, Realtek ALC257'
... many more lines ...
vmj INFO  2026-01-01 19:22:14 MidiEngine.info:261 - [0] Initializing MIDI synthesizer...
vmj INFO  2026-01-01 19:22:15 MidiEngine.<init>:341 - Synthesizer opened: name='Gervill', vendor='OpenJDK'
vmj INFO  2026-01-01 19:22:15 MidiEngine.<init>:347 - Sequencer transmitter connected to synthesizer receiver.
vmj INFO  2026-01-01 19:22:18 MidiEngine.info:261 - [0] Player ready

Thanks @ManakRaj-7 for the contribution to add these logs! Hopefully they will be helpful in getting us closer to finding a solution.

[ManakRaj-7]

Thanks @daveyarwood! Glad the diagnostics made it into the release. Hopefully the logs help narrow down the audio backend issue on affected distros. Happy to help further if needed.