Bug with Angular-Cli 6 : "Unknown option: '--extractCss'"

[atp-tha]

I create a project from fresh angular-cli template and upgrade it to Angular 6 following instructions from https://update.angular.io/. and run the project using Visual Studio.

An unhandled exception occurred while processing the request.
AggregateException: One or more errors occurred. (One or more errors occurred. (The NPM script 'start' exited without indicating that the Angular CLI was listening for requests. The error output was: Unknown option: '--extractCss'

))
System.Threading.Tasks.Task.GetResultCore(bool waitCompletionNotification)

InvalidOperationException: The NPM script 'start' exited without indicating that the Angular CLI was listening for requests. The error output was: Unknown option: '--extractCss'

Microsoft.AspNetCore.SpaServices.AngularCli.AngularCliMiddleware+d__3.MoveNext()

AggregateException: One or more errors occurred. (One or more errors occurred. (The NPM script 'start' exited without indicating that the Angular CLI was listening for requests. The error output was: Unknown option: '--extractCss'
))

But ng serve worked as expected.

The --extractCss option is unknown because it was removed and now use angular.json instead according to angular/angular-cli#10666.

From log above I believe C# code call angular-cli with --extractCss and listened for correct respond but it ended up error because angular-cli do not support --extractCss anymore.

[atp-tha]

Turned out the middleware is simply calling a script from package.json. Editing the scripts and set extractCss to true fixed it for me. This can be closed.