Fix some new warnings on nightly

src/checker.rs

@@ -602,17 +602,6 @@ mod tests {
     use super::*;
     use crate::config::testing::parse;
     use crate::symbol::Symbol;
-    use std::fmt::Debug;
-    use std::fmt::Display;
-
-    // Wraps a type T and makes it implement Debug by deferring to the Display implementation of T.
-    struct DebugAsDisplay<T: Display>(T);
-
-    impl<T: Display> Debug for DebugAsDisplay<T> {
-        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-            write!(f, "{}", self.0)
-        }
-    }
 
     fn checker_for_testing() -> Checker {
         Checker::new(

src/main.rs

@@ -3,6 +3,7 @@
 
 #![forbid(unsafe_code)]
 #![cfg_attr(not(feature = "ui"), allow(dead_code, unused_variables))]
+#![allow(clippy::assigning_clones)]
 
 mod build_script_checker;
 mod checker;

src/problem.rs

@@ -47,12 +47,6 @@ pub(crate) enum Problem {
     NewConfigVersionAvailable(i64),
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub(crate) struct ErrorDetails {
-    pub(crate) short: String,
-    pub(crate) detail: String,
-}
-
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub(crate) struct BinExecutionFailed {
     pub(crate) crate_sel: CrateSel,