Enable webpackbar for next build

[AndyBitz]

Feature request

Is your feature request related to a problem? Please describe.

I've came across the same problem a few times now. Sometimes when building it just hangs and nothings happens anymore, even though everything works fine during development.

I always need to go inside the node_modules folder or download, build and link next.js itself to debug.

For example, I changed packages/next/server/hot-reloader.js:

    const configs = await Promise.all([
      getBaseWebpackConfig(this.dir, { dev: true, isServer: false, config: this.config, buildId: this.buildId }),
      getBaseWebpackConfig(this.dir, { dev: true, isServer: true, config: this.config, buildId: this.buildId })
    ])

I replaced the dev: true with dev: false, started next dev and immediately saw that Terser seems to randomly fail due to this issue.

Describe the solution you'd like

Enable webpackbar for building, maybe with an config option.

Describe alternatives you've considered

Adding a --verbose argument to next build which would log the file that is currently processed etc.

I think this would make solving some issues much easier.