Having debugged this sort of thing before, it's actually really hard to figure that out.

The entire stack is kind of bad at both logging and having understandable error messages.

You get things like this:

    ╷
    │ Error: googleapi: Error 400: The request has errors, badRequest
    │ 
    │   with google_cloudfunctions_function.function,
    │   on main.tf line 46, in resource "google_cloudfunctions_function"         "function":
    │   46: resource "google_cloudfunctions_function" "function" ¨

Is this a problem with the actual terraform or passing a variable in or something? Is it a problem with the googleapi provider? Is it a problem with the API? Or did I, as the writer of this, simply forget a field?

In complex setups, this will be deep inside a module inside a module, and as the developer who did not use any google_cloudfunctions_function directly, you're left wondering what the heck is going on.