Dependency injection failure when manually invoking IServiceCollection.BuildServiceProvider

Is your question related to a specific version? If so, please specify:

I don’t think so, but we are using 3.0.14916.0, if that helps.

What language does your question apply to? (e.g. C#, JavaScript, Java, All)

C#.

Question

We have encountered a weird exception while the function host trying to activate a service:

Unable to resolve service for type 'Microsoft.Azure.WebJobs.Script.IEnvironment' while attempting to activate 'Microsoft.Azure.WebJobs.Script.Configuration.ScriptHostOptionsSetup'. 

We have traced this back to where we manually called IServiceCollection.BuildServiceProvider, and this exception is gone after we changed to use the ServiceProvider passed to our anonymous function as parameter from AddSingleton<TService>(this IServiceCollection services, Func<IServiceProvider, TService> implementationFactory) where TService : class.

This exception doesn’t reproduce when we run it locally in Visual Studio, but happens online after we deployed it to App Service.

I have looked into the source code mentioned in similar issue #6783, also found a usage of IServiceCollection.BuildServiceProvider.

Could you help us understand this situation, and probably come up with a way of preventing this from happening in future?

[bianyifan]

cc @OsmondJiang @junshi356 for awareness.

[bianyifan]

Well, I can’t reproduce this bug with the latest Azure Functions host extensions, probably this has been fixed in some commit. No further help needed, but thanks for your help anyway.