> I'm really not sure what you mean with this being different to the other derivings

No other derivings have an error when used like `#[deriving(Eq(int))]` etc. I guess it's not a particular problem to have one here, although really all derivings should be updated to not pass through these silent errors.

> The code you suggested used a `mitem.name()` and there's no such method in `mitem` 

Oh, sorry, you have to bring http://static.rust-lang.org/doc/master/syntax/attr/trait.AttrMetaMethods.html into scope.

It would've been nice to tell me that my suggestion didn't work, rather than just ignoring it. In any case, the other part of the suggestion (reducing the duplication of trait names) can be with or without talking the whole thing.