error[E0277]: `U` doesn't implement `std::fmt::Debug` | |
--> $DIR/derive-debug.rs:11:36 | |
| | |
11 | #[derivative(Debug(format_with="std::fmt::Debug::fmt"))] | |
| ^^^^^^^^^^^^^^^^^^^^^^ `U` cannot be formatted using `{:?}` because it doesn't implement `std::fmt::Debug` | |
| | |
= help: the trait `std::fmt::Debug` is not implemented for `U` | |
= help: consider adding a `where U: std::fmt::Debug` bound | |
= note: required by `std::fmt::Debug::fmt` |