A release Deezer's regional catalog omits is injected under a synthetic id,
and the only thing that can turn that id back into a release group is
`mb_catalog` / `apple_catalog` — two in-memory maps written only while an
artist page is built. Reaching such a record any other way fell through to
`api.deezer.com/album/{synthetic}`, which cannot resolve it, and the user was
told "album lookup failed".
Measured: King Gizzard's "The Silver Cord" (6660585962991362) failed cold in
237ms while the real Deezer single beside it (489399625) returned 14 tracks.
Three routes hit it — the sidebar's recent places, a replayed artist page
clicked before the fresh one lands, and the registries' 1000-entry clear.
That last one is why it looked intermittent.
Both registries now persist beside the MusicBrainz and Wikipedia bodies in
net-cache-v1, and the lookup reads memory, then disk, then Deezer. After the
fix the same cold lookup returns the record in 150ms.
The two structs deserialize as each other's type only if their required
fields happen to match, and they do not, so one entry can never be read as
the other kind.
KeelrLeek
4f485b6f9a