The music-app does have access to that directory because it uses the "unconfined" apparmor template which has wide open permissions. The apparmor profile is com.ubuntu.music_music_1.0.196 and I verified there are no denials and that the profile is wide open (/var/lib/apparmor/profiles/click_com.ubuntu.music_music_1.0.196).
However, ~/.cache/media-art is empty. What app is doing the thumbnailing, the music-app or the out of process mediascanner? If the music-app, the thumbnailer is written to write the files to somewhere in ~/.cache/com.ubuntu.music-- the path is determined based on the apparmor label. That said, ~/.cache/com.ubuntu.music does not exist here and creating it doesn't seem to make a difference.
The music-app does have access to that directory because it uses the "unconfined" apparmor template which has wide open permissions. The apparmor profile is com.ubuntu. music_music_ 1.0.196 and I verified there are no denials and that the profile is wide open (/var/lib/ apparmor/ profiles/ click_com. ubuntu. music_music_ 1.0.196) .
However, ~/.cache/media-art is empty. What app is doing the thumbnailing, the music-app or the out of process mediascanner? If the music-app, the thumbnailer is written to write the files to somewhere in ~/.cache/ com.ubuntu. music-- the path is determined based on the apparmor label. That said, ~/.cache/ com.ubuntu. music does not exist here and creating it doesn't seem to make a difference.