Make alsa find its plugins

Hi, this patch adds an environment variable, ALSA_PLUGIN_DIR to allow

it to find its plugins. This is especially useful in GuixSD where

pulseaudio is used by most applications. When running an application

that only knows about alsa, no sound can be output because the card is

taken by pulse. One solution is to use the pulseaudio plugin from

alsa-plugins:pulseaudio and setting ~/.asoundrc:

# Default to PulseAudio

pcm.!default {

type pulse

hint {

show on

description "Default ALSA Output (currently PulseAudio Sound

Server)" }

}

ctl.!default {

type pulse

}

But this results in an error because alsa will look for plugins in its

own output directory in the store. With this patch, alsa is able to

find its plugins in ALSA_PLUGIN_DIR after exporting it (export

ALSA_PLUGIN_DIR=$HOME/.guix-profile/lib/alsa-lib).

Hi Julien,

good idea!

The indentation in the patch files is off (alsa-lib uses tabs in its source code).

Also, what is 0001-Add-support-for-a-ALSA_PLUGIN_DIR-environment-variab.patch

embedded in this patch for? Maybe for upstream? Nice :)

You already patch the individual files in alsa-lib.

Note: It would be possible to use

++ char* plugdir = getenv("ALSA_PLUGIN_DIR") ?: ALSA_PLUGIN_DIR;

instead of

++ char* plugdir = ALSA_PLUGIN_DIR;

++ char* envplugdir = getenv("ALSA_PLUGIN_DIR");

++ if(envplugdir != NULL)

++ plugdir = envplugdir;

(especially since it's repeated multiple times) but maybe that's too obscure.

So LGTM except for the indentation and extra patch file!

Le Thu, 17 May 2018 08:01:43 +0200,

Danny Milosavljevic <dannym@scratchpost.org> a écrit :

Pushed as 2101cc3fb691f443b830fdf5f846ded5fa018739 on core-updates.