Change:
<!-- [31mICE[0m: Rustc '--edition=2021 -ooutputfile -Zdump-mir-dir=dir' 'error: internal compiler error: relating different kinds: {const error}: &'static str KeyNil', 'error: internal compiler error: relating different kinds: {const error}: &'static str KeyNil' File: --auto-reduced (treereduce-rust): &lt;details&lt;summary&lt;strongoriginal code&lt;/strong&lt;/summary&lt;poriginal: </p</detailsVersion information ` Command: <!-- Include a backtrace in the code block by setting in your environment. E.g. . --<details<summary<strongProgram output</strong</summary<p</p</details<!-- query stack: [typeck] type-checking [analysis] running analysis passes on this crate --
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for (obligation_arg, impl_arg) in std::iter::zip(obligation_trait_ref.args, impl_trait_ref.args) { <ins> if (obligation_arg, impl_arg).references_error() { return false; } </ins> if let Err(terr) = ocx.eq(&ObligationCause::dummy(), param_env, impl_arg, obligation_arg) {

aux_bins: vec![], aux_crates: vec![], revisions: vec![], <del> rustc_env: vec![("RUSTC_ICE".to_string(), "0".to_string())], </del> <ins> rustc_env: vec![ ("RUSTC_ICE".to_string(), "0".to_string()), ("RUST_BACKTRACE".to_string(), "short".to_string()), ], </ins> unset_rustc_env: vec![("RUSTC_LOG_COLOR".to_string())], exec_env: vec![], unset_exec_env: vec![],

let aux_dir = self.aux_output_dir(); self.build_all_auxiliary(&self.testpaths, &aux_dir, &mut rustc); <del> self.props.unset_rustc_env.iter().fold(&mut rustc, Command::env_remove); </del> rustc.envs(self.props.rustc_env.clone()); <ins> self.props.unset_rustc_env.iter().fold(&mut rustc, Command::env_remove); </ins> self.compose_and_run( rustc, self.config.compile_lib_path.to_str().unwrap(),

); aux_cx.build_all_auxiliary(of, &aux_dir, &mut aux_rustc); <ins> aux_rustc.envs(aux_props.rustc_env.clone()); </ins> for key in &aux_props.unset_rustc_env { aux_rustc.env_remove(key); } <del> aux_rustc.envs(aux_props.rustc_env.clone()); </del> let (aux_type, crate_type) = if is_bin { (AuxType::Bin, Some("bin"))

<ins> //! This test used to ICE in typeck because of the type/const mismatch, //! even though wfcheck already errored. //! issue: rust-lang/rust#123457 pub struct KeyHolder<const K: u8> {} pub trait ContainsKey<const K: u8> {} pub trait SubsetExcept<P> {} impl<K> ContainsKey<K> for KeyHolder<K> {} //~^ ERROR: type provided when a constant was expected //~| ERROR: type provided when a constant was expected impl<P, T: ContainsKey<0>> SubsetExcept<P> for T {} pub fn remove_key<K, S: SubsetExcept<K>>() -> S { loop {} } fn main() { let map: KeyHolder<0> = remove_key::<_, _>(); //~^ ERROR: the trait bound `KeyHolder<0>: SubsetExcept<_>` is not satisfied } </ins>

<ins> error[E0747]: type provided when a constant was expected --> $DIR/kind_mismatch.rs:11:38 | LL | impl<K> ContainsKey<K> for KeyHolder<K> {} |      -                               ^ |      | |      help: consider changing this type parameter to a const parameter: `const K: u8` error[E0747]: type provided when a constant was expected --> $DIR/kind_mismatch.rs:11:21 | LL | impl<K> ContainsKey<K> for KeyHolder<K> {} |      -              ^ |      | |      help: consider changing this type parameter to a const parameter: `const K: u8` error[E0277]: the trait bound `KeyHolder<0>: SubsetExcept<_>` is not satisfied --> $DIR/kind_mismatch.rs:22:45 | LL |     let map: KeyHolder<0> = remove_key::<_, _>(); |                                             ^ the trait `ContainsKey<0>` is not implemented for `KeyHolder<0>`, which is required by `KeyHolder<0>: SubsetExcept<_>` | note: required for `KeyHolder<0>` to implement `SubsetExcept<_>` --> $DIR/kind_mismatch.rs:15:28 | LL | impl<P, T: ContainsKey<0>> SubsetExcept<P> for T {} |            --------------  ^^^^^^^^^^^^^^^     ^ |            | |            unsatisfied trait bound introduced here note: required by a bound in `remove_key` --> $DIR/kind_mismatch.rs:17:25 | LL | pub fn remove_key<K, S: SubsetExcept<K>>() -> S { |                         ^^^^^^^^^^^^^^^ required by this bound in `remove_key` error: aborting due to 3 previous errors Some errors have detailed explanations: E0277, E0747. For more information about an error, try `rustc --explain E0277`. </ins>