Material-ui 1.2.1 support issue

[ouspark]

I am trying to upgrade material-ui to 1.2.1 version, the code generation fails with ...
scala.MatchError: {O}0 ,> {O}{U%}_exactProp.default({O}{U%}Portal.propTypes, "Portal")

Seems like the requiresjs does not support below kind of js definition.
Portal.propTypes = process.env.NODE_ENV !== "production" ? (0, _exactProp.default)(Portal.propTypes, 'Portal') : {};

Checkout js code at @material-ui/core/Portal/Portal.js