The track backfill listed every track with a NULL mbid, missing or
not, so each scan tried to open every missing file and logged an
"open failed" warning per track. Nothing ever healed. The album
backfill could pick a missing track as the one to read, and since
that pass is capped per scan, albums stuck that way were retried
ahead of the rest every time.
Both now read only tracks still on disk; an album with none left is
skipped until a scan finds its files again.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>