The trick we are using in Elixir test suite under similar situations (when we need to force the code to crash to test error handlers and similar) is to hide the value under Process.get(:unused_key, value). For example:
Process.get(:unused_key, 1) + "test"
The reason this works for now is because Process.get/2 will always return a dynamic value, so we cannot assume an error will happen. Maybe we will detect these cases in the future too… then you can ping us again. 
In any case, as the type system becomes smarter, it will be harder to hide compile time errors from it.
