}

        val assignmentTrace = assignmentTrace(resolution)
        val assignmentErrors = assignmentTrace.elements.filterIsInstance<AssignmentTraceElement.FailedToRecordAssignment>()
        if (assignmentErrors.isNotEmpty()) {
            failureReasons += AssignmentErrors(assignmentErrors)
        }

            data class FailuresInResolution(val errors: List<ResolutionError>) : StageFailure
            data class DocumentCheckFailures(val failures: List<DocumentCheckFailure>) : StageFailure
            data class AssignmentErrors(val usages: List<AssignmentTraceElement.FailedToRecordAssignment>) : StageFailure
        }
    }
}


val <R : StepResult> EvaluationResult<R>.stepResultOrPartialResult
    get() = when (this) {

                is StageFailure.NoSchemaAvailable -> appendLine("No associated schema for ${stageFailure.scriptContext}")
                is StageFailure.AssignmentErrors -> {
                    appendLine("Failures in assignments:".indent(1))
                    stageFailure.usages.forEach { unassigned ->
                        appendLine(describedUnassignedValueUsage(unassigned).indent(2))