npm package versions 1.x.x are broken

[janus-toendering]

File lib/ViewportSensor.js or lib/ViewportSensor/index.js is missing in npm package.

In file lib/viewport.js:6 we have

var ViewportSensor_1 = require("./ViewportSensor");

but the file is missing in the node module when installing libreact with either npm or yarn.

[janus-toendering]

Looks to me like it has been missing since 0.2.0. Am I missing something here? I am not able to build using the most simple webpack config (Webpack 4, babel with baben-env and -react, defaults otherwise)