[Feature Request] Attach more useful location information to config-related errors

## Feature Request

Errors like the one in #8522 are currently very hard for users to diagnose because they don't provide enough information to know what the actual source of the problem is. We can fix that, so I'm filing a task for myself.

Start by reading issue #8522 to understand the config-related error being discussed and what source information is currently missing. Trace that error through the project to identify where location details are attached; done means the resulting errors provide enough information for users to diagnose the actual source of the problem.

Written by the indexing model from the issue text.