I eventually found a fix for it. First of, it seems that I was missing a dependency on tracker-miner-fs. I am surprised that gnome-music did not pulled it as a dependency.
Then I followed the instructions on post #1 in https://bbs.archlinux.org/viewtopic.php?id=180249 TLDR: did a tracker-control -rcs followed by a for i in ~/Music/{*,*/*,*/*/*,*/*/*/*}; do tracker-control -f "$i"; done to force re-indexing. Hope this helps, Ghis
