MPD ERROR: Failed to open audio output after re-installing

Question

Having MPD v.0.19 and Ubuntu 15.04 for quite some time now I wanted to check out the latest version 0.20 thus downloaded it and followed the instructions to compile it on my own.

Unfortunately this did not work out so I want to fall back to the official .deb MPD v0.19.

Now after re-installing mpd by sudo apt-get purge mpd && sudo apt-get install mpd the following pops up when I try to play a song:

cat /var/log/mpd/mpd.log:

Nov 05 14:22 : client: [13] opened from local
ALSA lib confmisc.c:768:(parse_card) cannot find card '0'
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_card_driver returned error: No such file or directory
ALSA lib confmisc.c:392:(snd_func_concat) error evaluating strings
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_concat returned error: No such file or directory
ALSA lib confmisc.c:1251:(snd_func_refer) error evaluating name
ALSA lib conf.c:4260:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:4739:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2267:(snd_pcm_open_noupdate) Unknown PCM default
Nov 05 14:22 : alsa_output: Failed to open "My ALSA Device" [alsa]: Failed to open ALSA device "default": No such file or directory
Nov 05 14:22 : output: Failed to open audio output
Nov 05 14:22 : client: [13] closed

mpd -v:

config_file: loading file /etc/mpd.conf
errno: Failed to open /etc/mpd.conf: Permission denied

ls -la /etc/mpd.conf:

-rw-r----- 1 mpd audio 14092 Jun 23 00:05 /etc/mpd.conf

mpd.conf:

# An example configuration file for MPD.
# Read the user manual for documentation: http://www.musicpd.org/doc/user/
# or /usr/share/doc/mpd/user-manual.html


# Files and directories #######################################################
#
# This setting controls the top directory which MPD will search to discover the
# available audio files and add them to the daemon's online database. This 
# setting defaults to the XDG directory, otherwise the music directory will be
# be disabled and audio files will only be accepted over ipc socket (using
# file:// protocol) or streaming files over an accepted protocol.
#
music_directory     "/var/lib/mpd/music"
#
# This setting sets the MPD internal playlist directory. The purpose of this
# directory is storage for playlists created by MPD. The server will use 
# playlist files not created by the server but only if they are in the MPD
# format. This setting defaults to playlist saving being disabled.
#
playlist_directory      "/var/lib/mpd/playlists"
#
# This setting sets the location of the MPD database. This file is used to
# load the database at server start up and store the database while the 
# server is not up. This setting defaults to disabled which will allow
# MPD to accept files over ipc socket (using file:// protocol) or streaming
# files over an accepted protocol.
#
db_file         "/var/lib/mpd/tag_cache"
# 
# These settings are the locations for the daemon log files for the daemon.
# These logs are great for troubleshooting, depending on your log_level
# settings.
#
# The special value "syslog" makes MPD use the local syslog daemon. This
# setting defaults to logging to syslog, otherwise logging is disabled.
#
log_file            "/var/log/mpd/mpd.log"
#
# This setting sets the location of the file which stores the process ID
# for use of mpd --kill and some init scripts. This setting is disabled by
# default and the pid file will not be stored.
#
pid_file            "/run/mpd/pid"
#
# This setting sets the location of the file which contains information about
# most variables to get MPD back into the same general shape it was in before
# it was brought down. This setting is disabled by default and the server 
# state will be reset on server start up.
#
state_file          "/var/lib/mpd/state"
#
# The location of the sticker database.  This is a database which
# manages dynamic information attached to songs.
#
sticker_file                   "/var/lib/mpd/sticker.sql"
#
###############################################################################


# General music daemon options ################################################
#
# This setting specifies the user that MPD will run as. MPD should never run as
# root and you may use this setting to make MPD change its user ID after
# initialization. This setting is disabled by default and MPD is run as the
# current user.
#
user                "mpd"
#
# This setting specifies the group that MPD will run as. If not specified
# primary group of user specified with "user" setting will be used (if set).
# This is useful if MPD needs to be a member of group such as "audio" to
# have permission to use sound card.
#
#group                          "nogroup"
#
# This setting sets the address for the daemon to listen on. Careful attention
# should be paid if this is assigned to anything other then the default, any.
# This setting can deny access to control of the daemon. Choose any if you want
# to have mpd listen on every address. Not effective if systemd socket
# activation is in use.
#
# For network
bind_to_address     "localhost"
#
# And for Unix Socket
#bind_to_address        "/run/mpd/socket"
#
# This setting is the TCP port that is desired for the daemon to get assigned
# to.
#
#port               "6600"
#
# This setting controls the type of information which is logged. Available 
# setting arguments are "default", "secure" or "verbose". The "verbose" setting
# argument is recommended for troubleshooting, though can quickly stretch
# available resources on limited hardware storage.
#
#log_level          "default"
#
# If you have a problem with your MP3s ending abruptly it is recommended that 
# you set this argument to "no" to attempt to fix the problem. If this solves
# the problem, it is highly recommended to fix the MP3 files with vbrfix
# (available as vbrfix in the debian archive), at which
# point gapless MP3 playback can be enabled.
#
#gapless_mp3_playback           "yes"
#
# Setting "restore_paused" to "yes" puts MPD into pause mode instead
# of starting playback after startup.
#
#restore_paused "no"
#
# This setting enables MPD to create playlists in a format usable by other
# music players.
#
#save_absolute_paths_in_playlists   "no"
#
# This setting defines a list of tag types that will be extracted during the 
# audio file discovery process. The complete list of possible values can be
# found in the mpd.conf man page.
#metadata_to_use    "artist,album,title,track,name,genre,date,composer,performer,disc"
#
# This setting enables automatic update of MPD's database when files in 
# music_directory are changed.
#
#auto_update    "yes"
#
# Limit the depth of the directories being watched, 0 means only watch
# the music directory itself.  There is no limit by default.
#
#auto_update_depth "3"
#
###############################################################################


# Symbolic link behavior ######################################################
#
# If this setting is set to "yes", MPD will discover audio files by following 
# symbolic links outside of the configured music_directory.
#
#follow_outside_symlinks    "yes"
#
# If this setting is set to "yes", MPD will discover audio files by following
# symbolic links inside of the configured music_directory.
#
#follow_inside_symlinks     "yes"
#
###############################################################################


# Zeroconf / Avahi Service Discovery ##########################################
#
# If this setting is set to "yes", service information will be published with
# Zeroconf / Avahi.
#
#zeroconf_enabled       "yes"
#
# The argument to this setting will be the Zeroconf / Avahi unique name for
# this MPD server on the network.
#
#zeroconf_name          "Music Player"
#
###############################################################################


# Permissions #################################################################
#
# If this setting is set, MPD will require password authorization. The password
# can setting can be specified multiple times for different password profiles.
#
#password                        "password@read,add,control,admin"
#
# This setting specifies the permissions a user has who has not yet logged in. 
#
#default_permissions             "read,add,control,admin"
#
###############################################################################


# Database #######################################################################
#

#database {
#       plugin "proxy"
#       host "other.mpd.host"
#       port "6600"
#}

# Input #######################################################################
#

input {
        plugin "curl"
#       proxy "proxy.isp.com:8080"
#       proxy_user "user"
#       proxy_password "password"
}

#
###############################################################################

# Audio Output ################################################################
#
# MPD supports various audio output types, as well as playing through multiple 
# audio outputs at the same time, through multiple audio_output settings 
# blocks. Setting this block is optional, though the server will only attempt
# autodetection for one sound card.
#
# An example of an ALSA output:
#
audio_output {
    type        "alsa"
    name        "My ALSA Device"
#   device      "hw:0,0"    # optional
#   mixer_type      "hardware"      # optional
#   mixer_device    "default"   # optional
#   mixer_control   "PCM"       # optional
#   mixer_index "0"     # optional
}
#
# An example of an OSS output:
#
#audio_output {
#   type        "oss"
#   name        "My OSS Device"
#   device      "/dev/dsp"  # optional
#   mixer_type      "hardware"      # optional
#   mixer_device    "/dev/mixer"    # optional
#   mixer_control   "PCM"       # optional
#}
#
# An example of a shout output (for streaming to Icecast):
#
#audio_output {
#   type        "shout"
#   encoding    "ogg"           # optional
#   name        "My Shout Stream"
#   host        "localhost"
#   port        "8000"
#   mount       "/mpd.ogg"
#   password    "hackme"
#   quality     "5.0"
#   bitrate     "128"
#   format      "44100:16:1"
#   protocol    "icecast2"      # optional
#   user        "source"        # optional
#   description "My Stream Description" # optional
#   url             "http://example.com"    # optional
#   genre       "jazz"          # optional
#   public      "no"            # optional
#   timeout     "2"         # optional
#   mixer_type      "software"              # optional
#}
#
# An example of a recorder output:
#
#audio_output {
#       type            "recorder"
#       name            "My recorder"
#       encoder         "vorbis"                # optional, vorbis or lame
#       path            "/var/lib/mpd/recorder/mpd.ogg"
##      quality         "5.0"                   # do not define if bitrate is defined
#       bitrate         "128"                   # do not define if quality is defined
#       format          "44100:16:1"
#}
#
# An example of a httpd output (built-in HTTP streaming server):
#
#audio_output {
#   type        "httpd"
#   name        "My HTTP Stream"
#   encoder     "vorbis"        # optional, vorbis or lame
#   port        "8000"
#   bind_to_address "0.0.0.0"               # optional, IPv4 or IPv6
#   quality     "5.0"           # do not define if bitrate is defined
#   bitrate     "128"           # do not define if quality is defined
#   format      "44100:16:1"
#   max_clients     "0"                     # optional 0=no limit
#}
#
# An example of a pulseaudio output (streaming to a remote pulseaudio server)
# Please see README.Debian if you want mpd to play through the pulseaudio
# daemon started as part of your graphical desktop session!
#
#audio_output {
#   type        "pulse"
#   name        "My Pulse Output"
#   server      "remote_server"     # optional
#   sink        "remote_server_sink"    # optional
#}
#
# An example of a winmm output (Windows multimedia API).
#
#audio_output {
#   type        "winmm"
#   name        "My WinMM output"
#   device      "Digital Audio (S/PDIF) (High Definition Audio Device)" # optional
#       or
#   device      "0"     # optional
#   mixer_type  "hardware"  # optional
#}
#
# An example of an openal output.
#
#audio_output {
#   type        "openal"
#   name        "My OpenAL output"
#   device      "Digital Audio (S/PDIF) (High Definition Audio Device)" # optional
#}
#
## Example "pipe" output:
#
#audio_output {
#   type        "pipe"
#   name        "my pipe"
#   command     "aplay -f cd 2>/dev/null"
## Or if you're want to use AudioCompress
#   command     "AudioCompress -m | aplay -f cd 2>/dev/null"
## Or to send raw PCM stream through PCM:
#   command     "nc example.org 8765"
#   format      "44100:16:2"
#}
#
## An example of a null output (for no audio output):
#
#audio_output {
#   type        "null"
#   name        "My Null Output"
#   mixer_type      "none"                  # optional
#}
#
# If MPD has been compiled with libsamplerate support, this setting specifies 
# the sample rate converter to use.  Possible values can be found in the 
# mpd.conf man page or the libsamplerate documentation. By default, this is
# setting is disabled.
#
#samplerate_converter       "Fastest Sinc Interpolator"
#
###############################################################################


# Normalization automatic volume adjustments ##################################
#
# This setting specifies the type of ReplayGain to use. This setting can have
# the argument "off", "album", "track" or "auto". "auto" is a special mode that
# chooses between "track" and "album" depending on the current state of
# random playback. If random playback is enabled then "track" mode is used.
# See <http://www.replaygain.org> for more details about ReplayGain.
# This setting is off by default.
#
#replaygain         "album"
#
# This setting sets the pre-amp used for files that have ReplayGain tags. By
# default this setting is disabled.
#
#replaygain_preamp      "0"
#
# This setting sets the pre-amp used for files that do NOT have ReplayGain tags.
# By default this setting is disabled.
#
#replaygain_missing_preamp  "0"
#
# This setting enables or disables ReplayGain limiting.
# MPD calculates actual amplification based on the ReplayGain tags
# and replaygain_preamp / replaygain_missing_preamp setting.
# If replaygain_limit is enabled MPD will never amplify audio signal
# above its original level. If replaygain_limit is disabled such amplification
# might occur. By default this setting is enabled.
#
#replaygain_limit       "yes"
#
# This setting enables on-the-fly normalization volume adjustment. This will
# result in the volume of all playing audio to be adjusted so the output has 
# equal "loudness". This setting is disabled by default.
#
#volume_normalization       "no"
#
###############################################################################


# Character Encoding ##########################################################
#
# If file or directory names do not display correctly for your locale then you 
# may need to modify this setting.
#
filesystem_charset      "UTF-8"
#
# This setting controls the encoding that ID3v1 tags should be converted from.
#
id3v1_encoding          "UTF-8"
#
###############################################################################


# SIDPlay decoder #############################################################
#
# songlength_database:
#  Location of your songlengths file, as distributed with the HVSC.
#  The sidplay plugin checks this for matching MD5 fingerprints.
#  See http://www.c64.org/HVSC/DOCUMENTS/Songlengths.faq
#
# default_songlength:
#  This is the default playing time in seconds for songs not in the
#  songlength database, or in case you're not using a database.
#  A value of 0 means play indefinitely.
#
# filter:
#  Turns the SID filter emulation on or off.
#
#decoder {
#       plugin                  "sidplay"
#       songlength_database     "/media/C64Music/DOCUMENTS/Songlengths.txt"
#       default_songlength      "120"
#       filter "true"
#}
#
###############################################################################

The sound of my system is working all fine, it's just MPD/MPC that can not play sound.

Any help is appreciated!

Solution

Stupid me ran sudo adduser mpd while trying to get the custom version from git working. This was problematic with the actual MPD.

Solution: sudo deluser mpd In case it fails due to the MPD still running:

ps aux | grep mpd

and

sudo kill -9 id-of-running-process

Enjoy!