diff --git a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
index 210532e56a5..266a80187c5 100644
--- a/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
+++ b/compiler/rustc_borrowck/src/type_check/constraint_conversion.rs
@@ -287,7 +287,7 @@ impl<'a, 'tcx> ConstraintConversion<'a, 'tcx> {
                     ocx.infcx.at(&ObligationCause::dummy_with_span(self.span), self.param_env),
                     ty,
                 )
-                .map_err(|_: Vec<ScrubbedTraitError>| NoSolution)
+                .map_err(|_: Vec<ScrubbedTraitError<'tcx>>| NoSolution)
             },
             "normalize type outlives obligation",
         )
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
index d2eb0cb5a7b..1e7bb63e6ea 100644
--- a/compiler/rustc_hir_analysis/src/coherence/orphan.rs
+++ b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -319,7 +319,8 @@ fn orphan_check<'tcx>(
         }
 
         let ty = if infcx.next_trait_solver() {
-            let mut fulfill_cx = <dyn traits::TraitEngine<'tcx, ScrubbedTraitError>>::new(&infcx);
+            let mut fulfill_cx =
+                <dyn traits::TraitEngine<'tcx, ScrubbedTraitError<'tcx>>>::new(&infcx);
             infcx
                 .at(&cause, ty::ParamEnv::empty())
                 .structurally_normalize(ty, &mut *fulfill_cx)
diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index f5d78430c97..c95649e2ffb 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -1,9 +1,5 @@
-use crate::solve::NextSolverError;
 use crate::traits::query::evaluate_obligation::InferCtxtExt as _;
-use crate::traits::{
-    self, FromSolverError, Obligation, ObligationCause, ObligationCtxt, OldSolverError,
-    SelectionContext,
-};
+use crate::traits::{self, Obligation, ObligationCause, ObligationCtxt, SelectionContext};
 
 use rustc_hir::def_id::DefId;
 use rustc_hir::lang_items::LangItem;
@@ -124,21 +120,19 @@ impl<'tcx> InferCtxtBuilder<'tcx> {
     /// bound for the closure and in part because it is convenient to
     /// have `'tcx` be free on this function so that we can talk about
     /// `K: TypeFoldable<TyCtxt<'tcx>>`.)
-    fn enter_canonical_trait_query<K, R, E>(
+    fn enter_canonical_trait_query<K, R>(
         self,
         canonical_key: &Canonical<'tcx, K>,
-        operation: impl FnOnce(&ObligationCtxt<'_, 'tcx, E>, K) -> Result<R, NoSolution>,
+        operation: impl FnOnce(&ObligationCtxt<'_, 'tcx>, K) -> Result<R, NoSolution>,
     ) -> Result<CanonicalQueryResponse<'tcx, R>, NoSolution>
     where
         K: TypeFoldable<TyCtxt<'tcx>>,
         R: Debug + TypeFoldable<TyCtxt<'tcx>>,
         Canonical<'tcx, QueryResponse<'tcx, R>>: ArenaAllocatable<'tcx>,
-        E: FromSolverError<'tcx, NextSolverError<'tcx>>
-            + FromSolverError<'tcx, OldSolverError<'tcx>>,
     {
         let (infcx, key, canonical_inference_vars) =
             self.build_with_canonical(DUMMY_SP, canonical_key);
-        let ocx = ObligationCtxt::new_generic(&infcx);
+        let ocx = ObligationCtxt::new(&infcx);
         let value = operation(&ocx, key)?;
         ocx.make_canonicalized_query_response(canonical_inference_vars, value)
     }
diff --git a/compiler/rustc_trait_selection/src/regions.rs b/compiler/rustc_trait_selection/src/regions.rs
index 3ef3f9ef358..5f986e22f51 100644
--- a/compiler/rustc_trait_selection/src/regions.rs
+++ b/compiler/rustc_trait_selection/src/regions.rs
@@ -28,7 +28,7 @@ impl<'tcx> InferCtxt<'tcx> {
                     ),
                     ty,
                 )
-                .map_err(|_: Vec<ScrubbedTraitError>| NoSolution)
+                .map_err(|_: Vec<ScrubbedTraitError<'tcx>>| NoSolution)
             } else {
                 Ok(ty)
             }
diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index b644f70eee4..3de4aee0927 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -225,7 +225,7 @@ impl<'tcx> FromSolverError<'tcx, NextSolverError<'tcx>> for FulfillmentError<'tc
     }
 }
 
-impl<'tcx> FromSolverError<'tcx, NextSolverError<'tcx>> for ScrubbedTraitError {
+impl<'tcx> FromSolverError<'tcx, NextSolverError<'tcx>> for ScrubbedTraitError<'tcx> {
     fn from_solver_error(_infcx: &InferCtxt<'tcx>, error: NextSolverError<'tcx>) -> Self {
         match error {
             NextSolverError::TrueError(_) => ScrubbedTraitError::TrueError,
diff --git a/compiler/rustc_trait_selection/src/solve/normalize.rs b/compiler/rustc_trait_selection/src/solve/normalize.rs
index 5e41e8e8ba9..4211129a4e1 100644
--- a/compiler/rustc_trait_selection/src/solve/normalize.rs
+++ b/compiler/rustc_trait_selection/src/solve/normalize.rs
@@ -253,7 +253,7 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for DeeplyNormalizeForDiagnosticsFolder<'_,
             ty,
             vec![None; ty.outer_exclusive_binder().as_usize()],
         )
-        .unwrap_or_else(|_: Vec<ScrubbedTraitError>| ty.super_fold_with(self))
+        .unwrap_or_else(|_: Vec<ScrubbedTraitError<'tcx>>| ty.super_fold_with(self))
     }
 
     fn fold_const(&mut self, ct: ty::Const<'tcx>) -> ty::Const<'tcx> {
@@ -262,6 +262,6 @@ impl<'tcx> TypeFolder<TyCtxt<'tcx>> for DeeplyNormalizeForDiagnosticsFolder<'_,
             ct,
             vec![None; ct.outer_exclusive_binder().as_usize()],
         )
-        .unwrap_or_else(|_: Vec<ScrubbedTraitError>| ct.super_fold_with(self))
+        .unwrap_or_else(|_: Vec<ScrubbedTraitError<'tcx>>| ct.super_fold_with(self))
     }
 }
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 333fd4556e3..397f9cf2638 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -54,7 +54,7 @@ impl<
 
 /// Used if you want to have pleasant experience when dealing
 /// with obligations outside of hir or mir typeck.
-pub struct ObligationCtxt<'a, 'tcx, E = ScrubbedTraitError> {
+pub struct ObligationCtxt<'a, 'tcx, E = ScrubbedTraitError<'tcx>> {
     pub infcx: &'a InferCtxt<'tcx>,
     engine: RefCell<Box<dyn TraitEngine<'tcx, E>>>,
 }
@@ -65,21 +65,12 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx, FulfillmentError<'tcx>> {
     }
 }
 
-impl<'a, 'tcx> ObligationCtxt<'a, 'tcx, ScrubbedTraitError> {
+impl<'a, 'tcx> ObligationCtxt<'a, 'tcx, ScrubbedTraitError<'tcx>> {
     pub fn new(infcx: &'a InferCtxt<'tcx>) -> Self {
         Self { infcx, engine: RefCell::new(<dyn TraitEngine<'tcx, _>>::new(infcx)) }
     }
 }
 
-impl<'a, 'tcx, E> ObligationCtxt<'a, 'tcx, E>
-where
-    E: FromSolverError<'tcx, NextSolverError<'tcx>> + FromSolverError<'tcx, OldSolverError<'tcx>>,
-{
-    pub fn new_generic(infcx: &'a InferCtxt<'tcx>) -> Self {
-        Self { infcx, engine: RefCell::new(<dyn TraitEngine<'tcx, _>>::new(infcx)) }
-    }
-}
-
 impl<'a, 'tcx, E> ObligationCtxt<'a, 'tcx, E>
 where
     E: FulfillmentErrorLike<'tcx>,
diff --git a/compiler/rustc_trait_selection/src/traits/fulfill.rs b/compiler/rustc_trait_selection/src/traits/fulfill.rs
index 8746cfa37e2..59802a26043 100644
--- a/compiler/rustc_trait_selection/src/traits/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/traits/fulfill.rs
@@ -856,16 +856,15 @@ impl<'tcx> FromSolverError<'tcx, OldSolverError<'tcx>> for FulfillmentError<'tcx
     }
 }
 
-impl<'tcx> FromSolverError<'tcx, OldSolverError<'tcx>> for ScrubbedTraitError {
+impl<'tcx> FromSolverError<'tcx, OldSolverError<'tcx>> for ScrubbedTraitError<'tcx> {
     fn from_solver_error(_infcx: &InferCtxt<'tcx>, error: OldSolverError<'tcx>) -> Self {
         match error.error {
             FulfillmentErrorCode::Select(_)
             | FulfillmentErrorCode::Project(_)
             | FulfillmentErrorCode::Subtype(_, _)
             | FulfillmentErrorCode::ConstEquate(_, _) => ScrubbedTraitError::TrueError,
-            FulfillmentErrorCode::Cycle(_) | FulfillmentErrorCode::Ambiguity { overflow: _ } => {
-                ScrubbedTraitError::Ambiguity
-            }
+            FulfillmentErrorCode::Ambiguity { overflow: _ } => ScrubbedTraitError::Ambiguity,
+            FulfillmentErrorCode::Cycle(cycle) => ScrubbedTraitError::Cycle(cycle),
         }
     }
 }
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 8fdf9c61c49..9aaa8adbd67 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -77,24 +77,26 @@ pub use rustc_infer::traits::*;
 /// error itself (except for if it's an ambiguity or true error).
 ///
 /// use [`ObligationCtxt::new_with_diagnostics`] to get a [`FulfillmentError`].
-#[derive(Copy, Clone, Debug)]
-pub enum ScrubbedTraitError {
+#[derive(Clone, Debug)]
+pub enum ScrubbedTraitError<'tcx> {
     /// A real error. This goal definitely does not hold.
     TrueError,
     /// An ambiguity. This goal may hold if further inference is done.
     Ambiguity,
+    /// An old-solver-style cycle error, which will fatal.
+    Cycle(Vec<PredicateObligation<'tcx>>),
 }
 
-impl ScrubbedTraitError {
+impl<'tcx> ScrubbedTraitError<'tcx> {
     fn is_true_error(&self) -> bool {
         match self {
             ScrubbedTraitError::TrueError => true,
-            ScrubbedTraitError::Ambiguity => false,
+            ScrubbedTraitError::Ambiguity | ScrubbedTraitError::Cycle(_) => false,
         }
     }
 }
 
-impl<'tcx> FulfillmentErrorLike<'tcx> for ScrubbedTraitError {
+impl<'tcx> FulfillmentErrorLike<'tcx> for ScrubbedTraitError<'tcx> {
     fn is_true_error(&self) -> bool {
         self.is_true_error()
     }
diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
index 860f50888a5..e170d7cae93 100644
--- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs
@@ -76,7 +76,7 @@ impl<'cx, 'tcx> At<'cx, 'tcx> {
         };
 
         if self.infcx.next_trait_solver() {
-            match crate::solve::deeply_normalize_with_skipped_universes::<_, ScrubbedTraitError>(
+            match crate::solve::deeply_normalize_with_skipped_universes::<_, ScrubbedTraitError<'tcx>>(
                 self, value, universes,
             ) {
                 Ok(value) => return Ok(Normalized { value, obligations: vec![] }),
diff --git a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
index e4d0a541219..54fa0749618 100644
--- a/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
+++ b/compiler/rustc_trait_selection/src/traits/query/type_op/implied_outlives_bounds.rs
@@ -267,7 +267,7 @@ pub fn compute_implied_outlives_bounds_compat_inner<'tcx>(
                         ocx.infcx.at(&ObligationCause::dummy(), param_env),
                         ty_a,
                     )
-                    .map_err(|_errs: Vec<ScrubbedTraitError>| NoSolution)?;
+                    .map_err(|_errs: Vec<ScrubbedTraitError<'tcx>>| NoSolution)?;
                 }
                 let mut components = smallvec![];
                 push_outlives_components(tcx, ty_a, &mut components);
diff --git a/compiler/rustc_traits/src/codegen.rs b/compiler/rustc_traits/src/codegen.rs
index 5defb817271..c73ececd1d1 100644
--- a/compiler/rustc_traits/src/codegen.rs
+++ b/compiler/rustc_traits/src/codegen.rs
@@ -9,8 +9,8 @@ use rustc_middle::traits::CodegenObligationError;
 use rustc_middle::ty::{self, TyCtxt, TypeVisitableExt};
 use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
 use rustc_trait_selection::traits::{
-    FulfillmentErrorCode, ImplSource, Obligation, ObligationCause, ObligationCtxt,
-    SelectionContext, Unimplemented,
+    ImplSource, Obligation, ObligationCause, ObligationCtxt, ScrubbedTraitError, SelectionContext,
+    Unimplemented,
 };
 use tracing::debug;
 
@@ -51,7 +51,7 @@ pub fn codegen_select_candidate<'tcx>(
     // all nested obligations. This is because they can inform the
     // inference of the impl's type parameters.
     // FIXME(-Znext-solver): Doesn't need diagnostics if new solver.
-    let ocx = ObligationCtxt::new_with_diagnostics(&infcx);
+    let ocx = ObligationCtxt::new(&infcx);
     let impl_source = selection.map(|obligation| {
         ocx.register_obligation(obligation);
     });
@@ -65,7 +65,7 @@ pub fn codegen_select_candidate<'tcx>(
         // Cycle errors are the only post-monomorphization errors possible; emit them now so
         // `rustc_ty_utils::resolve_associated_item` doesn't return `None` post-monomorphization.
         for err in errors {
-            if let FulfillmentErrorCode::Cycle(cycle) = err.code {
+            if let ScrubbedTraitError::Cycle(cycle) = err {
                 infcx.err_ctxt().report_overflow_obligation_cycle(&cycle);
             }
         }
diff --git a/compiler/rustc_traits/src/normalize_projection_ty.rs b/compiler/rustc_traits/src/normalize_projection_ty.rs
index 712abf6fcb3..b0a93b62dbf 100644
--- a/compiler/rustc_traits/src/normalize_projection_ty.rs
+++ b/compiler/rustc_traits/src/normalize_projection_ty.rs
@@ -7,9 +7,7 @@ use rustc_trait_selection::traits::error_reporting::TypeErrCtxtExt;
 use rustc_trait_selection::traits::query::{
     normalize::NormalizationResult, CanonicalAliasGoal, NoSolution,
 };
-use rustc_trait_selection::traits::{
-    self, FulfillmentError, FulfillmentErrorCode, ObligationCause, ObligationCtxt, SelectionContext,
-};
+use rustc_trait_selection::traits::{self, ObligationCause, ScrubbedTraitError, SelectionContext};
 use tracing::debug;
 
 pub(crate) fn provide(p: &mut Providers) {
@@ -29,8 +27,7 @@ fn normalize_canonicalized_projection_ty<'tcx>(
 
     tcx.infer_ctxt().enter_canonical_trait_query(
         &goal,
-        |ocx: &ObligationCtxt<'_, 'tcx, FulfillmentError<'tcx>>,
-         ParamEnvAnd { param_env, value: goal }| {
+        |ocx, ParamEnvAnd { param_env, value: goal }| {
             debug_assert!(!ocx.infcx.next_trait_solver());
             let selcx = &mut SelectionContext::new(ocx.infcx);
             let cause = ObligationCause::dummy();
@@ -50,7 +47,7 @@ fn normalize_canonicalized_projection_ty<'tcx>(
                 // that impl vars are constrained by the signature, for example).
                 if !tcx.sess.opts.actually_rustdoc {
                     for error in &errors {
-                        if let FulfillmentErrorCode::Cycle(cycle) = &error.code {
+                        if let ScrubbedTraitError::Cycle(cycle) = &error {
                             ocx.infcx.err_ctxt().report_overflow_obligation_cycle(cycle);
                         }
                     }
@@ -74,7 +71,7 @@ fn normalize_canonicalized_weak_ty<'tcx>(
 
     tcx.infer_ctxt().enter_canonical_trait_query(
         &goal,
-        |ocx: &ObligationCtxt<'_, 'tcx>, ParamEnvAnd { param_env, value: goal }| {
+        |ocx, ParamEnvAnd { param_env, value: goal }| {
             let obligations = tcx.predicates_of(goal.def_id).instantiate_own(tcx, goal.args).map(
                 |(predicate, span)| {
                     traits::Obligation::new(
@@ -100,7 +97,7 @@ fn normalize_canonicalized_inherent_projection_ty<'tcx>(
 
     tcx.infer_ctxt().enter_canonical_trait_query(
         &goal,
-        |ocx: &ObligationCtxt<'_, 'tcx>, ParamEnvAnd { param_env, value: goal }| {
+        |ocx, ParamEnvAnd { param_env, value: goal }| {
             let selcx = &mut SelectionContext::new(ocx.infcx);
             let cause = ObligationCause::dummy();
             let mut obligations = vec![];
diff --git a/compiler/rustc_traits/src/type_op.rs b/compiler/rustc_traits/src/type_op.rs
index 35b0ede9a2e..b6a59a4ad3a 100644
--- a/compiler/rustc_traits/src/type_op.rs
+++ b/compiler/rustc_traits/src/type_op.rs
@@ -43,13 +43,10 @@ fn type_op_eq<'tcx>(
     tcx: TyCtxt<'tcx>,
     canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Eq<'tcx>>>,
 ) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, ()>>, NoSolution> {
-    tcx.infer_ctxt().enter_canonical_trait_query(
-        &canonicalized,
-        |ocx: &ObligationCtxt<'_, 'tcx>, key| {
-            let (param_env, Eq { a, b }) = key.into_parts();
-            Ok(ocx.eq(&ObligationCause::dummy(), param_env, a, b)?)
-        },
-    )
+    tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, |ocx, key| {
+        let (param_env, Eq { a, b }) = key.into_parts();
+        Ok(ocx.eq(&ObligationCause::dummy(), param_env, a, b)?)
+    })
 }
 
 fn type_op_normalize<'tcx, T>(
@@ -98,13 +95,10 @@ fn type_op_subtype<'tcx>(
     tcx: TyCtxt<'tcx>,
     canonicalized: Canonical<'tcx, ParamEnvAnd<'tcx, Subtype<'tcx>>>,
 ) -> Result<&'tcx Canonical<'tcx, QueryResponse<'tcx, ()>>, NoSolution> {
-    tcx.infer_ctxt().enter_canonical_trait_query(
-        &canonicalized,
-        |ocx: &ObligationCtxt<'_, 'tcx>, key| {
-            let (param_env, Subtype { sub, sup }) = key.into_parts();
-            Ok(ocx.sup(&ObligationCause::dummy(), param_env, sup, sub)?)
-        },
-    )
+    tcx.infer_ctxt().enter_canonical_trait_query(&canonicalized, |ocx, key| {
+        let (param_env, Subtype { sub, sup }) = key.into_parts();
+        Ok(ocx.sup(&ObligationCause::dummy(), param_env, sup, sub)?)
+    })
 }
 
 fn type_op_prove_predicate<'tcx>(