A lint check attribute was overruled by a `forbid` directive set as an attribute on an enclosing scope, or on the command line with the `-F` option. Example of erroneous code: ```compile_fail,E0453 #![forbid(non_snake_case)] #[allow(non_snake_case)] fn main() { let MyNumber = 2; // error: allow(non_snake_case) overruled by outer // forbid(non_snake_case) } ``` The `forbid` lint setting, like `deny`, turns the corresponding compiler warning into a hard error. Unlike `deny`, `forbid` prevents itself from being overridden by inner attributes. If you're sure you want to override the lint check, you can change `forbid` to `deny` (or use `-D` instead of `-F` if the `forbid` setting was given as a command-line option) to allow the inner lint check attribute: ``` #![deny(non_snake_case)] #[allow(non_snake_case)] fn main() { let MyNumber = 2; // ok! } ``` Otherwise, edit the code to pass the lint check, and remove the overruled attribute: ``` #![forbid(non_snake_case)] fn main() { let my_number = 2; } ```