Deployment fails; test fails

[alxx]

This function can't be deployed on the current version of Azure; it simply says:

Deployment to resource group '[redacted]' failed.
Additional details from the underlying API that might be helpful: At least one resource deployment operation failed. Please list deployment operations for details. Please see https://aka.ms/arm-debug for usage details.

Activity Log on the resource just shows as loading forever, so there's nothing there.

The function does appear in the Resources anyway, but trying to test it, with or without the compulsory 'container' parameter, results in a runtime error:

Anonymously Hosted DynamicMethods Assembly: Cannot perform runtime binding on a null reference.