cargo fmt doesn't accept --message-format.

[eddyb]

This means it can't easily be invoked by tools (e.g. editors) that want to avoid dealing with multiline error messages.

#2817 is related, in that cargo fmt should probably accept most general Cargo flags.

cc @Manishearth @oli-obk Does cargo clippy do anything special here?

[oli-obk]

Clippy calls cargo check and forwards all arguments, so I presume message-format will work, too.

I think we need a general way to invoke drivers like rustfmt, clippy-driver and others. I opened an issue on the cargo repo a while ago: rust-lang/cargo#6356

Any discussion on my suggestions are very welcome