Failed to link channels at startup

When starting aura playout with configured engine channels it fails to connect the channels with the following log output:

engine                 | 2024-12-12 18:41:24,006:engine:INFO - Waiting for Liquidsoap to be running ... - [engine.py:108-start()]
engine-core            | Failed to link 'aura_engine_line_out_0:out_0' - 'alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FL': No such file or directory
engine-core            | Failed to link 'aura_engine_line_out_0:out_1' - 'alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FR': No such file or directory
engine-core            | Failed to link 'alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FL' - 'aura_engine_line_in_0:in_0': No such file or directory
engine-core            | Failed to link 'alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FR' - 'aura_engine_line_in_0:in_1': No such file or directory
engine                 | 2024-12-12 18:41:26,007:engine:INFO - Waiting for Liquidsoap to be running ... - [engine.py:108-start()]

It seems that liquidsoap is not running at that moment and therefore the channels do not exist yet.

Running these pipe-wire commands after the playout started connects the channels and the soundcard outputs the audio.

pw-link aura_engine_line_out_0:out_0 alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FL
pw-link aura_engine_line_out_0:out_1 alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FR
pw-link alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FL aura_engine_line_in_00:in_0
pw-link alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FR aura_engine_line_in_00:in_1

Steps to Reproduce

1. configure engine channels in .env file. e.g.:

AURA_ENGINE_OUTPUT_DEVICE=default
AURA_ENGINE_OUTPUT_CHANNEL_LEFT=alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FL
AURA_ENGINE_OUTPUT_CHANNEL_RIGHT=alsa_input.pci-0000_00_1b.0.analog-stereo:capture_FR
AURA_ENGINE_INPUT_DEVICE=default
AURA_ENGINE_INPUT_CHANNEL_LEFT=alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FL
AURA_ENGINE_INPUT_CHANNEL_RIGHT=alsa_output.pci-0000_00_1b.0.analog-stereo:playback_FR

2. start aura playout

Expected Result

The channels to be properly connected so that the soundcard outputs audio.

Actual Result

The channels are not connected, no audio at the soundcards output.

Environment

Debian 12, AURA 1.0.0-alpha5-hotfix1