Fetching every album in one unfiltered request avoided Lidarr's unguarded
per-artist path, but not the exception underneath it. Every album endpoint maps
through AlbumResource.ToResource, which selects the release with
SingleOrDefault(x => x.Monitored). An album with two monitored releases makes
that throw -- "Sequence contains more than one element" -- and the bulk call
loses the entire library to one bad row.
Keep the unfiltered call as the first attempt, since it is a single request and
is still the only path that skips albums whose artist metadata is missing. When
it fails, fall back to one request per artist. That cannot dodge the exception
either, but it confines the loss to whichever artist owns the offending album
and names them, which is the only practical way to find it in a large library.
Album failures are counted separately from artist failures because they do not
mean the same thing. Tracks come from a different endpoint with a different
mapper, so an artist whose albums cannot be fetched still gets indexed and still
matches; it is the cull that cannot run. The report distinguishes the two rather
than lumping them into one warning that overstates the damage.
Emma Thorpe