Subj : Re: aplay oddity
To   : All
From : Lawrence D?Oliveiro
Date : Fri Oct 24 2025 12:30:01

On Thu, 23 Oct 2025 19:09:02 +0100, Adrian wrote:

> If I do a cut and paste of the aplay command, it works fine. So the
> problem looks as though it is some thing to do with the python call.

I would try to confirm this by running the Python script (or at least
a copy of the part that does the aplay command) from a terminal
session. In other words, try to minimize all the differences between
the situation where you can successfully invoke the command, and the
one where you can?t.

> Both command line and python are running under the same user.

I suspect there is some issue with setup of environment variables
(e.g. $HOME) when running the script in the background versus
interactively.

> What I'm seeing logged by the python code is the following error :
>
> ALSA lib pcm_dmix.c:999:(snd_pcm_dmix_open) unable to open slave
> aplay: main:831 audio open error: Unknown error 524
>
> I've tried rebooting again, and an Internet search doesn't come up
> with anything for my particular problem (they all seem to be
> "nothing working").

I did a search for ?alsa Unknown error 524? and found this
<https://stackoverflow.com/questions/78913265/pygame-error-alsa-couldnt-open-audio-device-unknown-error-524-what-is-going>
where the error was fixed by putting something into the systemwide
ALSA config.

This would be consistent with my suspicion that the per-user setup
for your background versus interactive cases is not exactly the same.

--- PyGate Linux v1.5
 * Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)

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