Hi,
I just pushed an update to my Hurd distro build scripts for Fedora 26
at https://github.com/dm0-/gnuxc which also includes a translator for
/dev/audio. I've uploaded the translator source separately if anyone
else is interested:
https://github.com/dm0-/hurd-rump-audio
The README has details, but the summary is that the translator
pretends to be a Solaris audio device and acts as a rump kernel client
converting I/O to the NetBSD audio device. Since PulseAudio has a
Solaris module, this allows audio playback from any programs that use
PulseAudio without patching them or modifying their build processes.
(That includes IceCat/Firefox, so e.g. web video sites are fully
working with this.)
Feel free to fork it if it's useful.
Thanks.
David