I improved a lint to warn unused trait imports. This failed to merge, because the lint triggered for unused trait imports in cargo as designed, which causes cargotest to fail because of
#[deny(unused)]. As far as I can tell there is no way to tell cargo to pass
--cap-lints to rustc. So I am not sure how to proceed.
As is, this means new lint can't be merged until it is fixed in all cargotest crates, as well as existing requirement that it is fixed in all of rustc and rustdoc.