How to enable trim-diagnostic-paths in clippy?

[GordianDziwis]

With cargo build I get:

error[E0277]: the trait bound `Rc<str>: From<&std::string::String>` is not satisfied

and with cargo clippy:

error[E0277]: the trait bound `std::rc::Rc<str>: std::convert::From<&std::string::String>` is not satisfied

This does not help:

RUSTFLAGS="-Z trim-diagnostic-paths=true" cargo  clippy

Is this by design?

[flip1995]

We were having a bunch of issues with this feature and decided not to enable it when it was implemented in rustc. See: #7798 (and the linked issues + PR for details and long discussions)

The situation might have changed since we last attempted this. So looking into this might be an interesting project.