packages/react-server/core/logging/server.js
function errorInterceptor (level, msg, meta) {

	if (meta instanceof Error) {
		meta = {error: meta};
	} else if (meta && meta.status && meta.response) {
		meta = {error: meta};
	}

	if (_.isPlainObject(meta)) {
		// allow {error: <someError>} as a valid `meta`
		meta = _.mapValues(meta, normalizeError);
	}
	return meta;
}
function errorInterceptor (level, msg, meta) {

	if (meta instanceof Error) {
		meta = {error: meta};
	} else if (meta && meta.status && meta.response) {
		meta = {error: meta};
	}

	if (_.isPlainObject(meta)) {
		// allow {error: <someError>} as a valid `meta`
		meta = _.mapValues(meta, normalizeError);
	}
	return meta;
}
Error objects are weird.  Let's turn them into normal objects.