With `merge_derives` enabled, `rustfmt` (rustfmt 1.4.22-nightly (97d03010 2020-10-04)) changes: * `use foo::{bar}` to `use foo::bar` * `use foo::self` to `use foo` But it doesn't change `use foo::{self}` to `use foo`. Such statements can arise through automated refactoring and would be useful to transform.