Rotation is expensive: the ceiling is one full walk per configured backend,
and a deep genealogy is thousands of requests and tens of minutes. A caller
watching a terminal cannot tell that from a hang, so the wrappers say which
backend they moved to and what ended the attempt before it.
One build attempt, reported before it runs.
Rotation is expensive: the ceiling is one full walk per configured backend, and a deep genealogy is thousands of requests and tens of minutes. A caller watching a terminal cannot tell that from a hang, so the wrappers say which backend they moved to and what ended the attempt before it.