Not that I need to
aplay as root but it came across me and I wondered why it shouldn't work.
# aplay /home/bibek/apert.wav XDG_RUNTIME_DIR (/run/user/1000) is not owned by us (uid 0), but by uid 1000! (This could e g happen if you try to connect to a non-root PulseAudio as a root user, over the native protocol. Don't do that.) ALSA lib pcm_dmix.c:1024:(snd_pcm_dmix_open) unable to open slave aplay: main:722: audio open error: No such file or directory
I can see that it is giving me reasonable amount of details but I still don't understand.