Playback fails when using pipe backend

[xterm91]

Description

The session terminates shortly (3 seconds-ish) after starting when attempting to use the pipe audio backend.

Context

I'm attempting to run go-librespot in a Home Assistant add-on on a Raspberry Pi 4. The output is destined for a snapcast-server. The error does not occur if I route the audio to a dummy output. I've tried building from source and copying the prebuilt binary from the latest docker image.

Logs

The logs don't show any specific errors but I included logs showing that the session starts, chunks are fetched.

time="2026-01-22T11:27:27-07:00" level=debug msg="skipping packet PacketTypeMercuryEvent, len: 323"
time="2026-01-22T11:27:27-07:00" level=debug msg="selected format OGG_VORBIS_160 (c14d00e18fa85136f8c49ea6f3170848e2f7b4ea)" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="requested aes key for file c14d00e18fa85136f8c49ea6f3170848e2f7b4ea, gid: 1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=trace msg="found 2 cdn urls" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="fetched first chunk of 8, total size is 4158564 bytes" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="fetched chunk 2/7, size: 524288" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="fetched chunk 1/7, size: 524288" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="fetched chunk 3/7, size: 524288" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=debug msg="fetched chunk 7/7, size: 488548" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:27-07:00" level=trace msg="seek to 198620ms (diff: 198462ms, samples: 8759142, bytes: 4145735)" uri="spotify:track:1dHW6MypbqYUzRXAItBQ07"
time="2026-01-22T11:27:56-07:00" level=trace msg="sent dealer ping"
time="2026-01-22T11:28:26-07:00" level=trace msg="sent dealer ping"
time="2026-01-22T11:28:56-07:00" level=error msg="did not receive last pong from dealer, 60s passed"
time="2026-01-22T11:29:26-07:00" level=trace msg="received accesspoint ping"
time="2026-01-22T11:29:26-07:00" level=trace msg="received accesspoint pong ack"
time="2026-01-22T11:29:26-07:00" level=error msg="did not receive last pong from dealer, 90s passed"
time="2026-01-22T11:29:56-07:00" level=error msg="did not receive last pong from dealer, 120s passed"

Config

log_level: trace
audio_backend: pipe
audio_output_pipe: /var/run/snapfifo

[devgianlu]

The program is most likely hanging because it is trying to open a FIFO that has no readers. I have updated the FIFO code so that it fails if there are no readers: #285

Can you confirm this was the issue?

[xterm91]

Resolved

Fetching chunks gets blocked if there is no pipe reader. Not an issue with go-librespot.

[titilambert]

This breaks if go-librespot is started outside Snapcast.
Can we make this behavior optional ? with a setting ? Thanks

[devgianlu]

@titilambert Can you give an example of your use case?

[titilambert]

I'm using snapcast with the follow config

    stream = pipe:///tmp/fifo/go-spotify?name=gotify&mode=create&dryout_ms=2000&sampleformat=44100:16:2

and go-librespot with

zeroconf_enabled: true # Whether to keep the device discoverable at all times, even if authenticated via other means
zeroconf_port: 0 # The port to use for Zeroconf, 0 for random
credentials:
  type: zeroconf
  zeroconf:
    persist_credentials: false # Whether to persist zeroconf user credentials even after disconnecting

log_level: info # Log level configuration (trace, debug, info, warn, error)
#device_id: '' # Spotify device ID (auto-generated)
device_name: 'drakkarmin' # Spotify device name
device_type: speaker # Spotify device type (icon)
audio_backend: pipe # Audio backend to use (alsa, pipe, pulseaudio)
#audio_device: default # ALSA audio device to use for playback
#mixer_device: '' # ALSA mixer device for volume synchronization
#mixer_control_name: Master # ALSA mixer control name for volume synchronization
#audio_buffer_time: 500000 # Audio buffer time in microseconds, ALSA only
#audio_period_count: 4 # Number of periods to request, ALSA only
audio_output_pipe: '/tmp/fifo/go-spotify' # Path to a named pipe for audio output
audio_output_pipe_format: s16le # Audio output pipe format (s16le, s32le, f32le)
bitrate: 320 # Playback bitrate (96, 160, 320)
volume_steps: 20 # Volume steps count
initial_volume: 10 # Initial volume in steps (not applied to the mixer device)
external_volume: false # Whether volume is controlled externally
disable_autoplay: false # Whether autoplay of more songs should be disabled

but when go-librespot > 0.6.2 starts, it crashes because snapcast is not reading the fifo file...

[devgianlu]

@titilambert Open a separate issue, this one risks to get lost.

[titilambert]

@devgianlu thanks just created it