v6.4.0-alpha.0 swallows errors

[gajus]

Describe the bug

storybook quietly fails without surfacing errors in .stories.tsx files.

To Reproduce

import {
  storiesOf,
} from '@storybook/react';
import React from 'react';
import * as templates from '../templates';

for (const [name, template] of Object.entries(templates)) {
  // `storiesOf` is currently the only way (even though marked as "legacy") to generate dynamic stories.
  // It is the only way currently possible and they are not planning to remove it until there is a replacement.
  // https://github.com/storybookjs/storybook/issues/9828#issuecomment-781387767
  const subject = storiesOf('Templates/' + name);

  throw new Error('OK');
}

Additional context

I would expect to see some reference to error "OK".

However, build just completes without any errors:

info => Using cached manager
webpack built preview 56918557f0342b18a688 in 7818ms
╭───────────────────────────────────────────────────╮
│                                                   │
│   Storybook 6.4.0-alpha.0 started                 │
│   8.05 s for preview                              │
│                                                   │
│    Local:            http://localhost:6006/       │
│    On your network:  http://192.168.4.40:6006/    │
│                                                   │
╰───────────────────────────────────────────────────╯

[SebastianStehle]

I have the same issue with 6.4.9

e.g. when I have the following file

// test.js
export const foo = 1;
throw new Error('123');

and import that, the error is just swallowed.