I now using debianslug on my NSLU2 (V3.10). Well, not as simple as openslug to install but now it work fine.
Did you remember what debian package you installed to successfull compile nightlies on the slug ?
libid3tag0-dev, libid3tag0, libsqlite0-dev, libsqlite0, zlib1g-dev, zlib1g.
Then a make, make install as normal. You’ll want to copy the contrib/mt-daapd.conf file into /etc and edit it to taste.
You can probably take debian/init.d and copy it to /etc/init.d/mt-daapd, also. Should be good to go from there.
Yell if you need anything else.