## errors.RefMovedError


A conditional ref move found the ref elsewhere than `expected`.


Usage

``` python
errors.RefMovedError(
    message,
    *,
    key=None,
    kind=None,
)
```


Raised by [fork](testing.ObjectBackend.md#tether.testing.ObjectBackend.fork), [promote](testing.ObjectBackend.md#tether.testing.ObjectBackend.promote) and [merge](testing.ObjectBackend.md#tether.testing.ObjectBackend.merge) when the caller passed the head it reviewed and the ref no longer holds it (or exists when it was expected absent); nothing was written. The engine reports it as a plan gone stale: re-plan, and review what moved.