An unhandled exception occurred: Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.

[Nagendra2109]

Describe the Bug

After upgrading from Angular version 9 to Angular version 12 facing this webpack issue

Build is getting failed

• Generating browser application bundles (phase: setup)...An unhandled exception occurred: Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
• configuration.entry['main'] should not contain the item 'C:\DP-V12\dp-core-ui\node_modules\webpack-dev-server\client\index.js?http://0.0.0.0:0&sockPath=/sockjs-node' twice.
  -> All modules are loaded upon startup. The last one is exported.
  See "C:\Users\NAGEND~1.P\AppData\Local\Temp\ng-3ctuKX\angular-errors.log" for further details.
  npm ERR! code ELIFECYCLE
  npm ERR! syscall spawn
  npm ERR! file C:\WINDOWS\system32\cmd.exe
  npm ERR! errno ENOENT
  npm ERR! dp-core-ui-ng@0.0.0 start: node -max-old-space-size=2048 ./node_modules/@angular/cli/bin/ng serve --proxy-config proxy.config.json --port 4201
  npm ERR! spawn ENOENT
  npm ERR!
  npm ERR! Failed at the dp-core-ui-ng@0.0.0 start script.
  npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:

Minimal Reproduction

extra-webpack.config.js

const singleSpaAngularWebpack = require('single-spa-angular/lib/webpack').default;

module.exports = (config, options) => {
const singleSpaWebpackConfig = singleSpaAngularWebpack(config, options);

// Feel free to modify this webpack config however you'd like to
singleSpaWebpackConfig.devServer.historyApiFallback = true;

return singleSpaWebpackConfig;
};

Expected Behavior

Build should be successfull

Screenshots

If applicable, add screenshots to help explain your problem.

Environment

Libs
- @angular/core version: "~12.2.0"
- "@angular-builders/custom-webpack": "12.1.3",
- "webpack": "^5.41.1",
- "single-spa": "^5.0.4",
- "single-spa-angular": "5.0.2",

For Tooling issues:
- Node version: 12.14.1
- Platform:  Windows 
Others:

Additional Context

Add any other context about the problem here.

[arturovt]

Can you provide a minimal reproducible example?

[Nagendra2109]

Can you provide a minimal reproducible example?

Please find the Reproducible example in this repository

https://github.com/Nagendra2109/customwebpackissue

[arturovt]

I can't install dependencies: error An unexpected error occurred: "https://registry.yarnpkg.com/acn-iis-core-ui: Not found".

[Nagendra2109]

I can't install dependencies: error An unexpected error occurred: "https://registry.yarnpkg.com/acn-iis-core-ui: Not found".

Hi, Can you take pull now i have made changes.

Edit: I have removed the dependencies which were creating errors.

[Nagendra2109]

Did anyone checked this issue..?
can anyone please update on this...?