error: unknown format trait `notimplemented` --> $DIR/ifmt-unknown-trait.rs:2:16 | LL | format!("{:notimplemented}", "3"); | ^^^^^^^^^^^^^^ | = note: the only appropriate formatting traits are: - ``, which uses the `Display` trait - `?`, which uses the `Debug` trait - `e`, which uses the `LowerExp` trait - `E`, which uses the `UpperExp` trait - `o`, which uses the `Octal` trait - `p`, which uses the `Pointer` trait - `b`, which uses the `Binary` trait - `x`, which uses the `LowerHex` trait - `X`, which uses the `UpperHex` trait error: aborting due to 1 previous error