https://github.com/rust-lang/rust-clippy/issues/6984 error: wildcard matches only a single variant and will also match any future added variants --> serde_derive/src/internals/attr.rs:1918:9 | 1918 | _ => {} | ^ help: try this: `syn::Type::__TestExhaustive(_)` | note: the lint level is defined here --> serde_derive/src/lib.rs:18:22 | 18 | #![deny(clippy::all, clippy::pedantic)] | ^^^^^^^^^^^^^^^^ = note: `#[deny(clippy::match_wildcard_for_single_variants)]` implied by `#[deny(clippy::pedantic)]` = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wildcard_for_single_variants error: wildcard matches only a single variant and will also match any future added variants --> serde_derive/src/internals/receiver.rs:153:13 | 153 | _ => {} | ^ help: try this: `Type::__TestExhaustive(_)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wildcard_for_single_variants error: wildcard matches only a single variant and will also match any future added variants --> serde_derive/src/bound.rs:190:17 | 190 | _ => {} | ^ help: try this: `syn::Type::__TestExhaustive(_)` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wildcard_for_single_variants