no sound on many games on a pure alsa system

[Francesco149]

I'm running with no pulseaudio on a pure alsa setup, 64-bit flatpak built with --disable-system-helper.

McOsu plays audio just fine, except I had to manually select the sound device which was nil by default.

Every other game I've tried (Hotline Miami, Duke Nukem 3D: Megaton Edition, World of Goo, Terraria) is just silent.

I inspected the console output for Hotline Miami (https://gist.github.com/Francesco149/69c238cadbc3a701a33c60f019da2526#file-steam-nosound-hotline-miami-log-L104) and saw that it was correctly trying to use alsa but failed with connection refused, but I already know alsa works inside flatpak, as McOsu can play audio just fine.

I thought the issue was that it wasn't picking up my default sound device so I tried allowing it to see ~/.asoundrc and /etc/asound.conf with --filesystem but that didn't help.

I tried disabling all my virtual sound devices so my default sound device was card0, device0 but still no dice.

I realize this is a niche setup I'm on, but flatpak is a great tool to bring software that's tied to complex dependencies and GNU libc such as steam on minimalistic distros such as musl-based ones like void or sabotage where people often use pure alsa and it would be cool to have this fixed.

I can provide logs for more games if you want.

[TingPing]

I would ask does the sound work when ran on the host but I guess you can't run steam with your libc? This flatpak passes all devices through so in theory its just up to the games how they behave.

[Francesco149]

yeah, I doubt I can run steam installer outside of flatpak on my musl-based system (unless steam runtime comes with glibc and the installer doesn't rely on glibc), but I will try

well I wouldn't be surprised if the games I tested had poor alsa support, it's just puzzling how McOsu works perfectly, maybe the sound library it uses (bass iirc) just has a better alsa implementation

I will try to come up with more tests, lemme know if you can think of anything else

[Francesco149]

just set up a 32-bit glibc chroot with steam and sound works fine for Hotline Miami, so I don't think it's an issue with the game's ALSA support

seeing how McOsu had nil as a default device in flatpak steam, this leads me to believe that there's something wrong with the default device when pulse is missing

[Francesco149]

I just noticed, /dev/snd seems to be owned by "nfsnobody" inside the flatpak, is that normal?

 $ flatpak run --command=ls com.valvesoftware.Steam -l /dev/snd
total 0
drwxr-xr-x 2 nfsnobody nfsnobody      80 Jul 17 13:52 by-id
drwxr-xr-x 2 nfsnobody nfsnobody     120 Jul 17 13:52 by-path
crw-rw---- 1 nfsnobody nfsnobody 116,  9 Jul 17 13:52 controlC0
crw-rw---- 1 nfsnobody nfsnobody 116,  2 Jul 17 13:52 controlC1
crw-rw---- 1 nfsnobody nfsnobody 116, 14 Jul 17 13:52 controlC2
crw-rw---- 1 nfsnobody nfsnobody 116, 16 Jul 17 13:52 controlC3
crw-rw---- 1 nfsnobody nfsnobody 116, 11 Jul 17 13:55 pcmC0D0c
crw-rw---- 1 nfsnobody nfsnobody 116, 10 Jul 17 14:29 pcmC0D0p
crw-rw---- 1 nfsnobody nfsnobody 116, 12 Jul 17 13:52 pcmC0D1p
crw-rw---- 1 nfsnobody nfsnobody 116, 13 Jul 17 13:52 pcmC0D2c
crw-rw---- 1 nfsnobody nfsnobody 116,  7 Jul 17 13:52 pcmC1D10p
crw-rw---- 1 nfsnobody nfsnobody 116,  8 Jul 17 13:52 pcmC1D11p
crw-rw---- 1 nfsnobody nfsnobody 116,  3 Jul 17 13:52 pcmC1D3p
crw-rw---- 1 nfsnobody nfsnobody 116,  4 Jul 17 13:52 pcmC1D7p
crw-rw---- 1 nfsnobody nfsnobody 116,  5 Jul 17 13:52 pcmC1D8p
crw-rw---- 1 nfsnobody nfsnobody 116,  6 Jul 17 13:52 pcmC1D9p
crw-rw---- 1 nfsnobody nfsnobody 116, 15 Jul 17 13:52 pcmC2D0c
crw-rw---- 1 nfsnobody nfsnobody 116, 18 Jul 17 13:52 pcmC3D0c
crw-rw---- 1 nfsnobody nfsnobody 116, 17 Jul 17 13:52 pcmC3D0p
crw-rw---- 1 nfsnobody nfsnobody 116,  1 Jul 17 13:52 seq
crw-rw---- 1 nfsnobody nfsnobody 116, 33 Jul 17 13:52 timer

[nanonyme]

Flatpak spec says Pulseaudio is expected on target platforms and Flatpak authors are encouraged to rely on it FWIW

[TingPing]

Pulseaudio will be sandboxable at some point, so yea it is certainly recommended. This specific flatpak does pass all devices through though so this usage of alsa should work in that case. Might be worth discussing in the flatpak/flatpak repo.

[nanonyme]

@TingPing I meant as the spec expects PA, submitter is expected to run into issues with other flatpaks later even if Steam flatpak can be made to work without.

[Francesco149]

looking forward to sandboxed pulseadio! :)

but yeah, since audio works fine from a regular glibc chroot with steam and no pulseaudio, there's probably a way to fix this flatpak. I still haven't found any more clues as to what could be wrong other than somehow incorrect default device.

[nanonyme]

Just in case there might be some id/gid peculiarities with regards to the sandbox, I'd personally try to run id inside and outside the sandbox to make sure you are who you think you are

[Francesco149]

uid and gid appear to be right

$ flatpak run --command=id com.valvesoftware.Steam 
uid=1000(loli) gid=1000(loli) groups=1000(loli),65534(nfsnobody)
$ id
uid=1000(loli) gid=1000(loli) groups=3(tty),4(kvm),7(video),8(audio),10(users),1000(loli)

in the manual glibc chroot I had to change audio gid (it's 8 on my host system which did not match) to get audio working, but flatpak doesn't seem to have an audio group so it should be fine

[Francesco149]

is there any easy way to get alsa-utils inside the flatpak so I can do aplay -l and speaker-test?

[nanonyme]

@Francesco149 except apparently inside the flatpak you belong into group nfsnobody which incidentally has write access to the devices.

[nanonyme]

@Francesco149 there were some workarounds added for ALSA, can you please retest?

[dariox86]

I experience the same issue with the latest version. Without PulseAudio there is no sound for video playback inside the Steam client and Proton games simply crash. Installing PulseAudio everything works as expected, but I would like to be able to use it without PulseAudio.