Invalid `webpack` resolve alias

Why This Error Occurred

When overriding config.resolve.alias incorrectly in next.config.js webpack will throw an error because private-next-pages is not defined.

Possible Ways to Fix It

This is not a bug in Next.js, it's related to the user adding a custom webpack(config) config to next.config.js and overriding internals by not applying Next.js' aliases. Solution would be:

webpack(config) {
  config.resolve.alias = {
    ...config.resolve.alias,
    // your aliases
  }
}

Useful Links

• Related issue