Game runs fine, but there is no in-game sound. In-game videos do have sound.

Console output when running the game:
Running Ruiner
Pooling OS allocations (pool size: 1408 MB, maximum allocations: 9502).
Using binned2.
4.16.0-0+++UE4+Release-4.16 513 0
Disabling core dumps.
sh: xdg-user-dir: command not found
Warning: option --plugin-path no longer exists.
Warning: option --plugin-path no longer exists.
ALSA lib pcm_dmix.c:1108:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm_dmix.c:1108:(snd_pcm_dmix_open) unable to open slave
ALSA lib pcm_dmix.c:1108:(snd_pcm_dmix_open) unable to open slave
AL lib: (WW) alc_initconfig: Failed to initialize backend "pulse"
AL lib: (EE) UpdateDeviceParams: Failed to set 44100hz, got 48000hz instead

Obviously, the game tries to use PulseAudio and fails, because I don't use PulseAudio.
Is there a way to force the game use ALSA?