failure to detect hifiberry DAC
*Created by: abcnorio*
please see below:
```
root@raspberrypi:/home/pi/mpd-configure# LANG=C aplay -l | grep ^card
card 0: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 []
root@raspberrypi:/home/pi/mpd-configure# DEBUG="True" INCLUDE_COMMENTS="True" bash mpd-configure
DEBUG mpd-configure *** script mpd-configure is being run; using SCRIPT_DIR `.'..
DEBUG mpd-configure *** debugging turned on by user..
DEBUG mpd-configure *** will source ALSA_CAPABILITIES_SCRIPT `./alsa-capabilities' ....
DEBUG mpd-configure *** ... done..
DEBUG mpd-configure *** CONFS_ENABLED: `./confs-enabled/*.conf'..
DEBUG mpd-configure *** PREFERENCES_FILE sourced: `./mpd-configure.conf'.
DEBUG mpd-configure *** CONF_MPD_NETWORK_ADRESS set to default: `0.0.0.0'..
DEBUG mpd-configure *** No potential problems found..
DEBUG mpd-configure *** start main function `do_configure' ....
DEBUG mpd-configure :
entering function `do_configure',
with arguments `'.
mpd-configure: line 1043: debug_function_ac: command not found
DEBUG mpd-configure :
entering function `fetch_alsa_hwaddresses',
with arguments `'.
====================================================================================================
DEBUG *** alsa-capabilities (1306): Using `/usr/bin/aplay' as aplay command.
====================================================================================================
DEBUG *** alsa-capabilities ( 371): aplay -l output line: `card 0: sndrpihifiberry [snd_rpi_hifiberry_dac], device 0: HifiBerry DAC HiFi pcm5102a-hifi-0 []'. with OPT_CUSTOMFILTER:
Error:
could not fetch interface label
```
device/ OS: RPi1, raspbian stretch, kernel 4.9.59+.
Thanks.
issue