modern boilerplate: npm build does not work

[psartini]

This issue has been opened with sencha support as well: https://support.sencha.com/#ticket-45559

npm start works as expected.
npm run build does not work.

It stops with this output and opens a browser window:

Child html-webpack-plugin for "index.html":
1 asset
Entrypoint undefined = index.html
[../node_modules/html-webpack-plugin/lib/loader.js!./index.html] 475 bytes {0} [built]
+ 3 hidden modules

Tried the latest repo version as of today. Versions are:
ext-webpack-plugin v6.6.3, Ext JS v6.6.0.258 Commercial Edition, Sencha Cmd v6.6.0.13, webpack v4.23.0, react v16.6.0

[mgusmano]

i will look at this