diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs index c9ba8e6dc8c..727285e4927 100644 --- a/compiler/rustc_trait_selection/src/traits/select/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs @@ -1366,11 +1366,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { && !other.value.skip_binder().has_escaping_bound_vars(); if value_same_except_bound_vars { // See issue #84398. In short, we can generate multiple ParamCandidates which are - // the same except for unused bound vars. Just pick the current one (the should - // both evaluate to the same answer). This is probably best characterized as a - // "hack", since we might prefer to just do our best to *not* create essentially - // duplicate candidates in the first place. - true + // the same except for unused bound vars. Just pick the one with the fewest bound vars + // or the current one if tied (they should both evaluate to the same answer). This is + // probably best characterized as a "hack", since we might prefer to just do our + // best to *not* create essentially duplicate candidates in the first place. + other.value.bound_vars().len() <= victim.value.bound_vars().len() } else if other.value == victim.value && victim.constness == Constness::NotConst { // Drop otherwise equivalent non-const candidates in favor of const candidates. true