Enum: Unknown attribute "format_with" for trait Debug

[simonsilvalauinger]

Trying to use format_with for Debug within an enum, leads into this error.

use derivative::*;
#[derive(Derivative)]
#[derivative(Debug)]
#[repr(u8)]
enum Enum {
    #[derivative(Debug(format_with = "hex_fmt"))]
    A,
}

Is there a chance to fix this?