google-chrome can't read alsa.conf / audio playback fails

[ivan]

Describe the bug

google-chrome can't read alsa.conf, presumably because of Chrome/Chromium's audio sandbox. Chromium in nixpkgs gets patched to support the /nix/store/... paths needed for ALSA.

On my machine that requires dmix (specified in alsa.conf), I usually do not hear audio output in Chrome.

To Reproduce
Steps to reproduce the behavior:

1. On NixOS master, install google-chrome and run google-chrome-stable
2. Observe:

ALSA lib conf.c:3956:(snd_config_update_r) Cannot access file /nix/store/ykkyj86i3hdnb47wa49kvrwjwh7amdzz-alsa-lib-1.1.9/share/alsa/alsa.conf
ALSA lib conf.c:3956:(snd_config_update_r) Cannot access file /nix/store/ykkyj86i3hdnb47wa49kvrwjwh7amdzz-alsa-lib-1.1.9/share/alsa/alsa.conf
ALSA lib conf.c:3956:(snd_config_update_r) Cannot access file /nix/store/ykkyj86i3hdnb47wa49kvrwjwh7amdzz-alsa-lib-1.1.9/share/alsa/alsa.conf
ALSA lib pcm.c:2635:(snd_pcm_open_noupdate) Unknown PCM default
[10914:10914:0801/132524.153092:ERROR:alsa_util.cc(204)] PcmOpen: default,No such file or directory
ALSA lib conf.c:3956:(snd_config_update_r) Cannot access file /nix/store/ykkyj86i3hdnb47wa49kvrwjwh7amdzz-alsa-lib-1.1.9/share/alsa/alsa.conf
ALSA lib pcm.c:2635:(snd_pcm_open_noupdate) Unknown PCM plug:default
[10914:10914:0801/132524.153269:ERROR:alsa_util.cc(204)] PcmOpen: plug:default,No such file or directory

Expected behavior

Working audio

Metadata
Please run nix run nixpkgs.nix-info -c nix-info -m and paste the result.

• system: "x86_64-linux"
• host os: Linux 4.19.62-hardened, NixOS, 19.09.git.cd22d6f (Loris)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 2.2.2
• channels(root): ""
• nixpkgs: /var/nixpkgs

Maintainer information:

# a list of nixpkgs attributes affected by the problem
attribute:
# a list of nixos modules affected by the problem
module:

[ivan]

I attempted this fix, but Chrome is not a happy camper

diff --git a/pkgs/applications/networking/browsers/google-chrome/default.nix b/pkgs/applications/networking/browsers/google-chrome/default.nix
index b0ae61c761d..2f21484e32a 100644
--- a/pkgs/applications/networking/browsers/google-chrome/default.nix
+++ b/pkgs/applications/networking/browsers/google-chrome/default.nix
@@ -129,6 +129,10 @@ in stdenv.mkDerivation rec {
       patchelf --set-rpath $rpath $elf
       patchelf --set-interpreter "$(cat $NIX_CC/nix-support/dynamic-linker)" $elf
     done
+
+    # Let the audio sandbox read alsa.conf
+    # We can't use ${alsaLib}/share/alsa/ because that string is longer than the one we're replacing
+    sed -i -e 's,/usr/share/alsa/,/nix/store/\x00\x00\x00\x00\x00,g' $out/share/google/$appname/chrome
   '';

   meta = {

[1:4:0801/135507.441816:ERROR:render_media_log.cc(27)] MediaEvent: MEDIA_ERROR_LOG_ENTRY {"error":"audio render error"}
[1:1:0801/135507.442259:ERROR:render_media_log.cc(27)] MediaEvent: PIPELINE_ERROR AUDIO_RENDERER_ERROR
[1:4:0801/135508.191290:ERROR:render_media_log.cc(27)] MediaEvent: MEDIA_ERROR_LOG_ENTRY {"error":"audio render error"}
[1:1:0801/135508.274973:ERROR:render_media_log.cc(27)] MediaEvent: PIPELINE_ERROR AUDIO_RENDERER_ERROR

[stale]

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