having RPI3 with Kodi leia v18
pifi digi+ is recognized by aplay -l
card 2: sndrpihifiberry [snd_rpi_hifiberry_digi], device 0: HifiBerry Digi HiFi wm8804-spdif-0 
Subdevice #0: subdevice #0
can play with squeezelite.
but is is not available in OSMC / settings/system/audio :
How to enable pifi for OSMC?
I realized that it might be a rights problem.
dmix alsa is not working due to rights.
speaker-test -c 2 -t wav
Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
ALSA lib pcm_dmix.c:1018:(snd_pcm_dmix_open) unable to create IPC semaphore
Playback open error: -13,Permission denied
it is running as sudo.
anyone knowing which rights are required for audio and hifiberry which I can check?