The disk check proves no BYTES are left. This proves no ROWS are, which
fails differently and worse: a stale storage.blobs row with nothing
behind it means a reference was never released, and dedup_gc will skip
it forever because its count never reaches zero. Silent, permanent, and
invisible to a check that only looks at the filesystem.
Zero is the right assertion, not "fewer than before". By this point the
suite has deleted its users, their drives and everything cascading
beneath, and the disk check has already insisted the blob store is
empty. A non-zero registry beside an empty disk is exactly the
divergence the consistency jobs report — caught here first because one
number is easier to read than a findings list.
Degrades to a warning if the endpoint is unavailable rather than
failing, so a build without the admin dedup surface still runs the rest.
Edouard Vanbelle
6c5e53fee4