`ng build` stays in terminal using `--extra-webpack-config`

Question

In package.json using below exits the terminal as expected.

ng build --progress=false --configuration production

Now, I want to instrument my code as well as exit terminal. However, using --extra-webpack-config in build the terminal is not closed.

ng build --extra-webpack-config=./cypress/coverage.webpack.ts --progress=false --configuration production

any additional parameter to close terminal?