ReadonlyerrorThe error that would have escaped commit. Typed CauslError
subclasses are surfaced as-is so callers can instanceof against
the canonical taxonomy; non-engine throws from inside the user
callback flow through unchanged.
ReadonlystagedInput node ids whose value the staged writes had changed before the throw — useful as a debugging breadcrumb naming the partial write set that closed (for example) a derivation cycle.
ReadonlystatusDiscriminator tag.
Failure arm of SimulateResult: the simulated transaction would have escaped
commitwith a typed engine error.Remarks
The error is one of the structured
CauslErrorsubclasses —CycleError,NotAnInputNodeError,UnknownNodeError,NodeDisposedError,StaleTxError, or any other engine-emitted typed error. Caller branches oninstanceofrather thantry/catch. A throw out of the user-supplied callback that is not aCauslErroris also surfaced through this arm —simulatedoes not pretend to own the user's exception hierarchy.