Serviio 2.0 and Playlists
However first a big thank-you to the developers of this work of art! It has been the answer to some long running problems encountered by many restrictive and deprecated media software (softwares?).
I run Gentoo Linux on my main system which serves my audio and video files. I, since forever, have enjoyed creating music playlists for myself. When I found out that Serviio correctly shares playlists, I dropped playlist creation on the dlna client apps and made them on the Gentoo box (since for one reason or another I'd reinstall Serviio or its shares, and the client links would become stale).
Like most serious audiophiles, I keep my giant music folders on a separate drive (call it /mnt/arcade/Music). For convenience, I symlinked that folder to my home directory (call that /home/vaerc/Music), and made a 'playlist' folder dedicated to -guess what- playlists inside of it.
M3U playlists with absolute paths did NOT work for me. Neither did any other formats. They weren't visible on any of my networked dlna clients. Relative playlists worked fine, I could see them in the dlna menus. I would have been content with this, but local programs on the Gentoo box (VLC, etc) would not play these relative path playlists. I could either have A) two playlist copies, one relative and one absolute or B) solve this problem.
I found this post which got me started. It convinced me absolute paths could work, and I didn't have to waste gray matter making two of each playlist. Looking at Serviio's DEBUG logs, I found that while I was sharing the symlink "/home/vaerc/Music" in Serviio, my absolute path playlists were referencing files in "/mnt/arcade/Music".
Seeing this, I changed all my playlists to point to files through /home/vaerc/Music, instead of using the real paths. Like magic (but completely science-y) it worked! The playlists appeared on the clients! It seems that even if playlists reference the same files that Serviio is hosting, if the paths to get to them differ, Serviio will ignore the playlist file.
So, TL/DR: When making playlists, keep in mind the path to the folders you originally input into Serviio. Do use that path in making playlists, regardless of what symlink cleverness you got going on.
There!