extensions/ipynb/src/deserializers.ts/translateErrorOutput
function translateErrorOutput(output?: nbformat.IError): NotebookCellOutput {
	output = output || { output_type: 'error', ename: '', evalue: '', traceback: [] };
	return new NotebookCellOutput(
		[
			NotebookCellOutputItem.error({
				name: output?.ename || '',
				message: output?.evalue || '',
				stack: (output?.traceback || []).join('\n')
			})
		],
		{ ...getOutputMetadata(output), originalError: output }
	);
}