Uncaught (in promise) Error: Constructor for "app-root#undefined" was not found at initializeComponent

[newtonmunene99]

Stencil version:

  "@stencil/core": "^1.0.0-beta.0"

I'm submitting a:

[x] bug report
[ ] feature request
[ ] support request => Please do not submit support requests here, use one of these channels: https://stencil-worldwide.herokuapp.com/ or https://forum.ionicframework.com/

Current behavior:

Build fine but shows a blank white screen in browser with the following errors in the browser console ;

Uncaught (in promise) Error: Constructor for "app-root#undefined" was not found
    at initializeComponent

and I'm using firebase in my project. Getting this in browser console

SyntaxError: Identifier 'firebase$1' has already been declared

Expected behavior:

Should show my stencil app in the browser.
Steps to reproduce:

• Upgrade to stencil one beta
• npm start

[manucorporat]

I am pretty sure i can't reproduce following that steps, seems like there is some third party libraries involved, can you provide a repo case?

[newtonmunene99]

Here's is the repo for my project https://github.com/newtonmunene99/newtonmunene_public

[manucorporat]

After some initial debugging seems like rollup is emitting some duplicated identifiers, opened an issue:
rollup/rollup#2865