Publishing Azure Function to App Service fails with HTTP status code RequestTimeout

From https://developercommunity.visualstudio.com/content/problem/1080810/publishing-azure-function-to-app-service-fails-wit.html

I am completely unable to publish an Azure Function from Visual Studio to App Service.

The first problem is that the dialog displayed to the user is not helpful. It states “We are unable to determine the cause of the error. Check the output log for more details.”. It provides a path to an output log.

The second problem is that the output log doesn’t provide any information. It states the same thing as the dialog.

The only thing that provides any insight is the output window, which states “…failed with HTTP status code RequestTimeout.” This is the third problem.

Retrying never works. The publish always fails with ‘RequestTimeout’.

Start with the linked Developer Community report and reproduce publishing an Azure Function from Visual Studio to App Service. The payload names no repository file or test; done means the failure dialog and output log provide useful information about the RequestTimeout instead of only repeating a generic message.

Written by the indexing model from the issue text.