Bug: can't disable Webpack's Dev Server error overlay

[arsinclair]

Preflight Checklist

• I have read the contribution documentation for this project.
• I agree to follow the code of conduct that this project follows, as appropriate.
• I have searched the issue tracker for a bug that matches the one I want to file, without success.

Issue Details

• Electron Forge Version:
  • 6.0.0-beta.57
• Electron Version:
  • v11.3.0
• Operating System:
  • Debian GNU/Linux 10 (buster)

Expected Behavior

The webpack dev server has an error overlay when there're warnings or errors reported by eslint. There's a way to turn off this overlay per https://webpack.js.org/configuration/dev-server/#devserveroverlay, so I'm expecting to be able to modify the rendered/main webpack config file and have the overlay removed.

Actual Behavior

Disabling the error overlay for webpack dev server in the webpack config (both renderer and main) doesn't have any effect.

To Reproduce

The following configuration have been tried:

  devServer: {
    overlay: false
  }

and

  devServer: {
    overlay: {
      warnings: false,
      errors: false,
    }
  }

but no luck.