How to hook up alternate IServiceProvider implementation?

[DaRosenberg]

I'm trying to hook Autofac into my Blazor app, but I can't find any way to provide the actual IServiceProvider instance myself.

Here's an illustration of what I'm trying to do (as per Autofac documentation):

public class Startup
{
    public IContainer ApplicationContainer { get; private set; }

    public IServiceProvider ConfigureServices(IServiceCollection services)
    {
        var builder = new ContainerBuilder();
        builder.Populate(services);
        // Add some custom service and implementation to test whether it can be injected
        builder.RegisterType<DefaultSystemClock>().As<ISystemClock>();
        ApplicationContainer = builder.Build();

        // This return value seems to never be used by the WebAssemblyHostBuilder
        return new AutofacServiceProvider(ApplicationContainer);
    }

    public void Configure(IBlazorApplicationBuilder app)
    {
        app.AddComponent<App>("app");
    }
}

A quick glance into the source of WebAssemblyHostBuilder and ConventionBasedStartup seems to confirm that this is not how it's implemented (there's no code that take care of any return value from the ConfigureServices() method.

Is there some other hook I should be using to replace the default IServiceProvider implementation with the one provided by Autofac?

[csnewman]

Custom service providers are not current supported. However I have a PR #1623 open to enable support.

Also, I have Autofac working using my proposed changes.

[SteveSandersonMS]

Implemented in #4785