I woke up at 3am and debugged this. With a loose binary search, I narrowed it down to one song that is the source of the problem:
Uncle Salty by Aerosmith (from Toys in the Attic)
Nothing unusual about this song file (I’m listening to it as I type) especially relative to it’s brethren:
MPEG, 192 kbps, 44.1 kHz, -5.3db volume, MPEG Layer 3, ID3 tag v2.3
Would debug -d9 give us anything useful beyond the name of the file? I’ll be happy to do whatever it takes to debug if it helps advance mt-daapd.
I can also suggest some changes to the documentation (e.g., spaces in mp3_dir directory path elements are OK).