Rollup merge of #126075 - compiler-errors:remove-debugwithinfcx, r=lcnr

Remove `DebugWithInfcx` machinery

This PR removes `DebugWithInfcx` after having a lot of second thoughts about it due to recent type system uplifting work. We could add it back later if we want, but I don't think the amount of boilerplate in the complier and the existence of (kindof) hacks like `NoInfcx` currently justify the existence of `DebugWithInfcx`, especially since it's not even being used anywhere in the compiler currently.

The motivation for `DebugWithInfcx` is that we want to be able to print infcx-aware information, such as universe information[^1] (though if there are other usages that I'm overlooking, please let me know). I think there are probably more tailored solutions that can specifically be employed in places where this infcx-aware printing is necessary. For example, one way of achieving this is by implementing a custom `FmtPrinter` which overloads `ty_infer_name` (perhaps also extending it to have overrideable stubs for printing placeholders too) to print the `?u.i` name for an infer var. This will necessitate uplifting `Print` from `rustc_middle::ty::print`, but this seems a bit more extensible and reusable than `DebugWithInfcx`.

One of the problems w/ `DebugWithInfcx` is its opt-in-ness. Even if a compiler dev adds a new `debug!(ty)` in a context where there is an `infcx` we can access, they have to *opt-in* to using `DebugWithInfcx` with something like `debug!(infcx.with(ty))`. This feels to me like it risks a lot of boilerplate, and very easy to just forget adding it at all, especially in cases like `#[instrument]`.

A second problem is the `NoInfcx` type itself. It's necessary to have this dummy infcx implementation since we often want to print types outside of the scope of a valid `Infcx`. Right now, `NoInfcx` is only *partially* a valid implementation of `InferCtxtLike`, except for the methods that we specifically need for `DebugWithInfcx`. As I work on uplifting the trait solver, I actually want to add a lot more methods to `InferCtxtLike` and having to add `unreachable!("this should never be called")` stubs for uplifted methods like `next_ty_var` is quite annoying.

In reality, I actually only *really* care about the second problem -- we could, perhaps, instead just try to get rid of `NoInfcx` and just just duplicate `Debug` and `DebugWithInfcx` for most types. If we're okay with duplicating all these implementations (though most of them would just be trivial `#[derive(Debug, DebugWithInfcx)]`), I'd be okay with that too 🤔

r? `@BoxyUwU` `@lcnr` would like to know your thoughts -- happy to discuss this further, mainly trying to bring this problem up

[^1]: Which in my experience is only really necessary when we're debugging things like generalizer bugs.

17 files changed, 105 insertions, 477 deletions

diff --git a/compiler/rustc_middle/src/ty/list.rs b/compiler/rustc_middle/src/ty/list.rs
index 0db541899d2..71a93cc520d 100644
--- a/compiler/rustc_middle/src/ty/list.rs
+++ b/compiler/rustc_middle/src/ty/list.rs
@@ -1,5 +1,5 @@
 use super::flags::FlagComputation;
-use super::{DebruijnIndex, DebugWithInfcx, InferCtxtLike, TyCtxt, TypeFlags, WithInfcx};
+use super::{DebruijnIndex, TypeFlags};
 use crate::arena::Arena;
 use rustc_data_structures::aligned::{align_of, Aligned};
 use rustc_serialize::{Encodable, Encoder};
@@ -162,14 +162,6 @@ impl<H, T: fmt::Debug> fmt::Debug for RawList<H, T> {
         (**self).fmt(f)
     }
 }
-impl<'tcx, H, T: DebugWithInfcx<TyCtxt<'tcx>>> DebugWithInfcx<TyCtxt<'tcx>> for RawList<H, T> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        fmt::Debug::fmt(&this.map(|this| this.as_slice()), f)
-    }
-}
 
 impl<H, S: Encoder, T: Encodable<S>> Encodable<S> for RawList<H, T> {
     #[inline]
diff --git a/compiler/rustc_middle/src/ty/mod.rs b/compiler/rustc_middle/src/ty/mod.rs
index 7ff1b799822..83f8de6b6f9 100644
--- a/compiler/rustc_middle/src/ty/mod.rs
+++ b/compiler/rustc_middle/src/ty/mod.rs
@@ -61,7 +61,6 @@ use rustc_span::{ExpnId, ExpnKind, Span};
 use rustc_target::abi::{Align, FieldIdx, Integer, IntegerType, VariantIdx};
 pub use rustc_target::abi::{ReprFlags, ReprOptions};
 pub use rustc_type_ir::relate::VarianceDiagInfo;
-pub use rustc_type_ir::{DebugWithInfcx, InferCtxtLike, WithInfcx};
 use tracing::{debug, instrument};
 pub use vtable::*;
 
diff --git a/compiler/rustc_middle/src/ty/structural_impls.rs b/compiler/rustc_middle/src/ty/structural_impls.rs
index cc6b1d57f87..71e2e3e9f99 100644
--- a/compiler/rustc_middle/src/ty/structural_impls.rs
+++ b/compiler/rustc_middle/src/ty/structural_impls.rs
@@ -13,7 +13,7 @@ use rustc_ast_ir::visit::VisitorResult;
 use rustc_hir::def::Namespace;
 use rustc_span::source_map::Spanned;
 use rustc_target::abi::TyAndLayout;
-use rustc_type_ir::{ConstKind, DebugWithInfcx, InferCtxtLike, WithInfcx};
+use rustc_type_ir::ConstKind;
 
 use std::fmt::{self, Debug};
 
@@ -83,14 +83,6 @@ impl fmt::Debug for ty::LateParamRegion {
     }
 }
 
-impl<'tcx> ty::DebugWithInfcx<TyCtxt<'tcx>> for Ty<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        this.data.fmt(f)
-    }
-}
 impl<'tcx> fmt::Debug for Ty<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         with_no_trimmed_paths!(fmt::Debug::fmt(self.kind(), f))
@@ -121,70 +113,33 @@ impl<'tcx> fmt::Debug for ty::Clause<'tcx> {
     }
 }
 
-impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for Pattern<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match &**this.data {
-            ty::PatternKind::Range { start, end, include_end } => f
-                .debug_struct("Pattern::Range")
-                .field("start", start)
-                .field("end", end)
-                .field("include_end", include_end)
-                .finish(),
-        }
-    }
-}
-
 impl<'tcx> fmt::Debug for ty::consts::Expr<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::consts::Expr<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match this.data.kind {
+        match self.kind {
             ty::ExprKind::Binop(op) => {
-                let (lhs_ty, rhs_ty, lhs, rhs) = this.data.binop_args();
-                write!(
-                    f,
-                    "({op:?}: ({:?}: {:?}), ({:?}: {:?}))",
-                    &this.wrap(lhs),
-                    &this.wrap(lhs_ty),
-                    &this.wrap(rhs),
-                    &this.wrap(rhs_ty),
-                )
+                let (lhs_ty, rhs_ty, lhs, rhs) = self.binop_args();
+                write!(f, "({op:?}: ({:?}: {:?}), ({:?}: {:?}))", lhs, lhs_ty, rhs, rhs_ty,)
             }
             ty::ExprKind::UnOp(op) => {
-                let (rhs_ty, rhs) = this.data.unop_args();
-                write!(f, "({op:?}: ({:?}: {:?}))", &this.wrap(rhs), &this.wrap(rhs_ty))
+                let (rhs_ty, rhs) = self.unop_args();
+                write!(f, "({op:?}: ({:?}: {:?}))", rhs, rhs_ty)
             }
             ty::ExprKind::FunctionCall => {
-                let (func_ty, func, args) = this.data.call_args();
+                let (func_ty, func, args) = self.call_args();
                 let args = args.collect::<Vec<_>>();
-                write!(f, "({:?}: {:?})(", &this.wrap(func), &this.wrap(func_ty))?;
+                write!(f, "({:?}: {:?})(", func, func_ty)?;
                 for arg in args.iter().rev().skip(1).rev() {
-                    write!(f, "{:?}, ", &this.wrap(arg))?;
+                    write!(f, "{:?}, ", arg)?;
                 }
                 if let Some(arg) = args.last() {
-                    write!(f, "{:?}", &this.wrap(arg))?;
+                    write!(f, "{:?}", arg)?;
                 }
 
                 write!(f, ")")
             }
             ty::ExprKind::Cast(kind) => {
-                let (value_ty, value, to_ty) = this.data.cast_args();
-                write!(
-                    f,
-                    "({kind:?}: ({:?}: {:?}), {:?})",
-                    &this.wrap(value),
-                    &this.wrap(value_ty),
-                    &this.wrap(to_ty)
-                )
+                let (value_ty, value, to_ty) = self.cast_args();
+                write!(f, "({kind:?}: ({:?}: {:?}), {:?})", value, value_ty, to_ty)
             }
         }
     }
@@ -192,20 +147,12 @@ impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::consts::Expr<'tcx> {
 
 impl<'tcx> fmt::Debug for ty::Const<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::Const<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
         // If this is a value, we spend some effort to make it look nice.
-        if let ConstKind::Value(_, _) = this.data.kind() {
+        if let ConstKind::Value(_, _) = self.kind() {
             return ty::tls::with(move |tcx| {
                 // Somehow trying to lift the valtree results in lifetime errors, so we lift the
                 // entire constant.
-                let lifted = tcx.lift(*this.data).unwrap();
+                let lifted = tcx.lift(*self).unwrap();
                 let ConstKind::Value(ty, valtree) = lifted.kind() else {
                     bug!("we checked that this is a valtree")
                 };
@@ -215,7 +162,7 @@ impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for ty::Const<'tcx> {
             });
         }
         // Fall back to something verbose.
-        write!(f, "{kind:?}", kind = &this.map(|data| data.kind()))
+        write!(f, "{:?}", self.kind())
     }
 }
 
@@ -247,32 +194,12 @@ impl<'tcx> fmt::Debug for GenericArg<'tcx> {
         }
     }
 }
-impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for GenericArg<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match this.data.unpack() {
-            GenericArgKind::Lifetime(lt) => write!(f, "{:?}", &this.wrap(lt)),
-            GenericArgKind::Const(ct) => write!(f, "{:?}", &this.wrap(ct)),
-            GenericArgKind::Type(ty) => write!(f, "{:?}", &this.wrap(ty)),
-        }
-    }
-}
 
 impl<'tcx> fmt::Debug for Region<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?}", self.kind())
     }
 }
-impl<'tcx> DebugWithInfcx<TyCtxt<'tcx>> for Region<'tcx> {
-    fn fmt<Infcx: InferCtxtLike<Interner = TyCtxt<'tcx>>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        write!(f, "{:?}", &this.map(|data| data.kind()))
-    }
-}
 
 ///////////////////////////////////////////////////////////////////////////
 // Atomic structs
diff --git a/compiler/rustc_type_ir/src/binder.rs b/compiler/rustc_type_ir/src/binder.rs
index 9a2c9059967..e50d59ba5f0 100644
--- a/compiler/rustc_type_ir/src/binder.rs
+++ b/compiler/rustc_type_ir/src/binder.rs
@@ -8,12 +8,11 @@ use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
 use rustc_serialize::Decodable;
 use tracing::debug;
 
-use crate::debug::{DebugWithInfcx, WithInfcx};
 use crate::fold::{FallibleTypeFolder, TypeFoldable, TypeFolder, TypeSuperFoldable};
 use crate::inherent::*;
 use crate::lift::Lift;
 use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor};
-use crate::{self as ty, InferCtxtLike, Interner, SsoHashSet};
+use crate::{self as ty, Interner, SsoHashSet};
 
 /// Binder is a binder for higher-ranked lifetimes or types. It is part of the
 /// compiler's representation for things like `for<'a> Fn(&'a isize)`
@@ -56,18 +55,6 @@ where
     }
 }
 
-impl<I: Interner, T: DebugWithInfcx<I>> DebugWithInfcx<I> for ty::Binder<I, T> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        f.debug_tuple("Binder")
-            .field(&this.map(|data| data.as_ref().skip_binder()))
-            .field(&this.data.bound_vars())
-            .finish()
-    }
-}
-
 macro_rules! impl_binder_encode_decode {
     ($($t:ty),+ $(,)?) => {
         $(
diff --git a/compiler/rustc_type_ir/src/const_kind.rs b/compiler/rustc_type_ir/src/const_kind.rs
index 84d48e14c24..f1683f5449f 100644
--- a/compiler/rustc_type_ir/src/const_kind.rs
+++ b/compiler/rustc_type_ir/src/const_kind.rs
@@ -5,7 +5,7 @@ use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
 use rustc_type_ir_macros::{Lift_Generic, TypeFoldable_Generic, TypeVisitable_Generic};
 use std::fmt;
 
-use crate::{self as ty, DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
+use crate::{self as ty, DebruijnIndex, Interner};
 
 use self::ConstKind::*;
 
@@ -61,28 +61,19 @@ impl<I: Interner> PartialEq for ConstKind<I> {
 
 impl<I: Interner> fmt::Debug for ConstKind<I> {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-
-impl<I: Interner> DebugWithInfcx<I> for ConstKind<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
         use ConstKind::*;
 
-        match this.data {
+        match self {
             Param(param) => write!(f, "{param:?}"),
-            Infer(var) => write!(f, "{:?}", &this.wrap(var)),
+            Infer(var) => write!(f, "{:?}", &var),
             Bound(debruijn, var) => crate::debug_bound_var(f, *debruijn, var),
             Placeholder(placeholder) => write!(f, "{placeholder:?}"),
             Unevaluated(uv) => {
-                write!(f, "{:?}", &this.wrap(uv))
+                write!(f, "{:?}", &uv)
             }
-            Value(ty, valtree) => write!(f, "({valtree:?}: {:?})", &this.wrap(ty)),
+            Value(ty, valtree) => write!(f, "({valtree:?}: {:?})", &ty),
             Error(_) => write!(f, "{{const error}}"),
-            Expr(expr) => write!(f, "{:?}", &this.wrap(expr)),
+            Expr(expr) => write!(f, "{:?}", &expr),
         }
     }
 }
@@ -112,17 +103,9 @@ impl<I: Interner> UnevaluatedConst<I> {
 
 impl<I: Interner> fmt::Debug for UnevaluatedConst<I> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<I: Interner> DebugWithInfcx<I> for UnevaluatedConst<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
         f.debug_struct("UnevaluatedConst")
-            .field("def", &this.data.def)
-            .field("args", &this.wrap(this.data.args))
+            .field("def", &self.def)
+            .field("args", &self.args)
             .finish()
     }
 }
@@ -175,23 +158,6 @@ impl fmt::Debug for InferConst {
         }
     }
 }
-impl<I: Interner> DebugWithInfcx<I> for InferConst {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match *this.data {
-            InferConst::Var(vid) => match this.infcx.universe_of_ct(vid) {
-                None => write!(f, "{:?}", this.data),
-                Some(universe) => write!(f, "?{}_{}c", vid.index(), universe.index()),
-            },
-            InferConst::EffectVar(vid) => write!(f, "?{}e", vid.index()),
-            InferConst::Fresh(_) => {
-                unreachable!()
-            }
-        }
-    }
-}
 
 #[cfg(feature = "nightly")]
 impl<CTX> HashStable<CTX> for InferConst {
diff --git a/compiler/rustc_type_ir/src/debug.rs b/compiler/rustc_type_ir/src/debug.rs
deleted file mode 100644
index c206f3ccdb5..00000000000
--- a/compiler/rustc_type_ir/src/debug.rs
+++ /dev/null
@@ -1,146 +0,0 @@
-use crate::{
-    ConstVid, EffectVid, FloatVid, InferCtxtLike, IntVid, Interner, RegionVid, TyVid, UniverseIndex,
-};
-
-use core::fmt;
-use std::marker::PhantomData;
-
-pub struct NoInfcx<I>(PhantomData<I>);
-
-impl<I: Interner> InferCtxtLike for NoInfcx<I> {
-    type Interner = I;
-
-    fn interner(&self) -> Self::Interner {
-        unreachable!()
-    }
-
-    fn universe_of_ty(&self, _ty: TyVid) -> Option<UniverseIndex> {
-        None
-    }
-
-    fn universe_of_lt(&self, _lt: RegionVid) -> Option<UniverseIndex> {
-        None
-    }
-
-    fn universe_of_ct(&self, _ct: ConstVid) -> Option<UniverseIndex> {
-        None
-    }
-
-    fn opportunistic_resolve_ty_var(&self, vid: TyVid) -> I::Ty {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn opportunistic_resolve_int_var(&self, vid: IntVid) -> I::Ty {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn opportunistic_resolve_float_var(&self, vid: FloatVid) -> I::Ty {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn opportunistic_resolve_ct_var(&self, vid: ConstVid) -> I::Const {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn opportunistic_resolve_effect_var(&self, vid: EffectVid) -> I::Const {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn opportunistic_resolve_lt_var(&self, vid: crate::RegionVid) -> I::Region {
-        panic!("cannot resolve {vid:?}")
-    }
-
-    fn defining_opaque_types(&self) -> I::DefiningOpaqueTypes {
-        Default::default()
-    }
-}
-
-pub trait DebugWithInfcx<I: Interner>: fmt::Debug {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result;
-}
-
-impl<I: Interner, T: DebugWithInfcx<I> + ?Sized> DebugWithInfcx<I> for &'_ T {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        <T as DebugWithInfcx<I>>::fmt(this.map(|&data| data), f)
-    }
-}
-
-impl<I: Interner, T: DebugWithInfcx<I>> DebugWithInfcx<I> for [T] {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        match f.alternate() {
-            true => {
-                write!(f, "[\n")?;
-                for element in this.data.iter() {
-                    write!(f, "{:?},\n", &this.wrap(element))?;
-                }
-                write!(f, "]")
-            }
-            false => {
-                write!(f, "[")?;
-                if this.data.len() > 0 {
-                    for element in &this.data[..(this.data.len() - 1)] {
-                        write!(f, "{:?}, ", &this.wrap(element))?;
-                    }
-                    if let Some(element) = this.data.last() {
-                        write!(f, "{:?}", &this.wrap(element))?;
-                    }
-                }
-                write!(f, "]")
-            }
-        }
-    }
-}
-
-pub struct WithInfcx<'a, Infcx: InferCtxtLike, T> {
-    pub data: T,
-    pub infcx: &'a Infcx,
-}
-
-impl<Infcx: InferCtxtLike, T: Copy> Copy for WithInfcx<'_, Infcx, T> {}
-
-impl<Infcx: InferCtxtLike, T: Clone> Clone for WithInfcx<'_, Infcx, T> {
-    fn clone(&self) -> Self {
-        Self { data: self.data.clone(), infcx: self.infcx }
-    }
-}
-
-impl<'a, I: Interner, T> WithInfcx<'a, NoInfcx<I>, T> {
-    pub fn with_no_infcx(data: T) -> Self {
-        Self { data, infcx: &NoInfcx(PhantomData) }
-    }
-}
-
-impl<'a, Infcx: InferCtxtLike, T> WithInfcx<'a, Infcx, T> {
-    pub fn new(data: T, infcx: &'a Infcx) -> Self {
-        Self { data, infcx }
-    }
-
-    pub fn wrap<U>(self, u: U) -> WithInfcx<'a, Infcx, U> {
-        WithInfcx { data: u, infcx: self.infcx }
-    }
-
-    pub fn map<U>(self, f: impl FnOnce(T) -> U) -> WithInfcx<'a, Infcx, U> {
-        WithInfcx { data: f(self.data), infcx: self.infcx }
-    }
-
-    pub fn as_ref(&self) -> WithInfcx<'a, Infcx, &T> {
-        WithInfcx { data: &self.data, infcx: self.infcx }
-    }
-}
-
-impl<Infcx: InferCtxtLike, T: DebugWithInfcx<Infcx::Interner>> fmt::Debug
-    for WithInfcx<'_, Infcx, T>
-{
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        DebugWithInfcx::fmt(self.as_ref(), f)
-    }
-}
diff --git a/compiler/rustc_type_ir/src/inherent.rs b/compiler/rustc_type_ir/src/inherent.rs
index 205a1e5f100..2fc765f1c8f 100644
--- a/compiler/rustc_type_ir/src/inherent.rs
+++ b/compiler/rustc_type_ir/src/inherent.rs
@@ -12,11 +12,11 @@ use rustc_ast_ir::Mutability;
 use crate::fold::{TypeFoldable, TypeSuperFoldable};
 use crate::relate::Relate;
 use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable};
-use crate::{self as ty, CollectAndApply, DebugWithInfcx, Interner, UpcastFrom};
+use crate::{self as ty, CollectAndApply, Interner, UpcastFrom};
 
 pub trait Ty<I: Interner<Ty = Self>>:
     Copy
-    + DebugWithInfcx<I>
+    + Debug
     + Hash
     + Eq
     + Into<I::GenericArg>
@@ -116,7 +116,7 @@ pub trait Safety<I: Interner<Safety = Self>>: Copy + Debug + Hash + Eq + TypeVis
 
 pub trait Region<I: Interner<Region = Self>>:
     Copy
-    + DebugWithInfcx<I>
+    + Debug
     + Hash
     + Eq
     + Into<I::GenericArg>
@@ -134,7 +134,7 @@ pub trait Region<I: Interner<Region = Self>>:
 
 pub trait Const<I: Interner<Const = Self>>:
     Copy
-    + DebugWithInfcx<I>
+    + Debug
     + Hash
     + Eq
     + Into<I::GenericArg>
@@ -166,7 +166,7 @@ pub trait GenericsOf<I: Interner<GenericsOf = Self>> {
 
 pub trait GenericArgs<I: Interner<GenericArgs = Self>>:
     Copy
-    + DebugWithInfcx<I>
+    + Debug
     + Hash
     + Eq
     + IntoIterator<Item = I::GenericArg>
diff --git a/compiler/rustc_type_ir/src/interner.rs b/compiler/rustc_type_ir/src/interner.rs
index ad1d2753b28..b7f412ecb8e 100644
--- a/compiler/rustc_type_ir/src/interner.rs
+++ b/compiler/rustc_type_ir/src/interner.rs
@@ -9,7 +9,7 @@ use crate::ir_print::IrPrint;
 use crate::relate::Relate;
 use crate::solve::inspect::CanonicalGoalEvaluationStep;
 use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable};
-use crate::{self as ty, DebugWithInfcx};
+use crate::{self as ty};
 
 pub trait Interner:
     Sized
@@ -32,7 +32,7 @@ pub trait Interner:
     type GenericArgs: GenericArgs<Self>;
     type GenericArgsSlice: Copy + Debug + Hash + Eq + Deref<Target = [Self::GenericArg]>;
     type GenericArg: Copy
-        + DebugWithInfcx<Self>
+        + Debug
         + Hash
         + Eq
         + IntoKind<Kind = ty::GenericArgKind<Self>>
@@ -74,9 +74,9 @@ pub trait Interner:
 
     // Things stored inside of tys
     type ErrorGuaranteed: Copy + Debug + Hash + Eq;
-    type BoundExistentialPredicates: Copy + DebugWithInfcx<Self> + Hash + Eq + Relate<Self>;
+    type BoundExistentialPredicates: Copy + Debug + Hash + Eq + Relate<Self>;
     type AllocId: Copy + Debug + Hash + Eq;
-    type Pat: Copy + Debug + Hash + Eq + DebugWithInfcx<Self> + Relate<Self>;
+    type Pat: Copy + Debug + Hash + Eq + Debug + Relate<Self>;
     type Safety: Safety<Self> + TypeFoldable<Self> + Relate<Self>;
     type Abi: Abi<Self> + TypeFoldable<Self> + Relate<Self>;
 
@@ -86,7 +86,7 @@ pub trait Interner:
     type ParamConst: Copy + Debug + Hash + Eq + ParamLike;
     type BoundConst: Copy + Debug + Hash + Eq + BoundVarLike<Self>;
     type ValueConst: Copy + Debug + Hash + Eq;
-    type ExprConst: Copy + DebugWithInfcx<Self> + Hash + Eq + Relate<Self>;
+    type ExprConst: Copy + Debug + Hash + Eq + Relate<Self>;
 
     // Kinds of regions
     type Region: Region<Self>;
diff --git a/compiler/rustc_type_ir/src/lib.rs b/compiler/rustc_type_ir/src/lib.rs
index 7072b3de07d..a76e278cc05 100644
--- a/compiler/rustc_type_ir/src/lib.rs
+++ b/compiler/rustc_type_ir/src/lib.rs
@@ -42,7 +42,6 @@ mod macros;
 mod binder;
 mod canonical;
 mod const_kind;
-mod debug;
 mod flags;
 mod generic_arg;
 mod infcx;
@@ -59,7 +58,6 @@ pub use canonical::*;
 #[cfg(feature = "nightly")]
 pub use codec::*;
 pub use const_kind::*;
-pub use debug::{DebugWithInfcx, WithInfcx};
 pub use flags::*;
 pub use generic_arg::*;
 pub use infcx::InferCtxtLike;
diff --git a/compiler/rustc_type_ir/src/predicate.rs b/compiler/rustc_type_ir/src/predicate.rs
index 63a4c2e9d1f..c0713dc50d2 100644
--- a/compiler/rustc_type_ir/src/predicate.rs
+++ b/compiler/rustc_type_ir/src/predicate.rs
@@ -9,7 +9,7 @@ use crate::inherent::*;
 use crate::lift::Lift;
 use crate::upcast::Upcast;
 use crate::visit::TypeVisitableExt as _;
-use crate::{self as ty, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
+use crate::{self as ty, Interner};
 
 /// `A: 'region`
 #[derive(derivative::Derivative)]
@@ -248,16 +248,6 @@ pub enum ExistentialPredicate<I: Interner> {
     AutoTrait(I::DefId),
 }
 
-// FIXME: Implement this the right way after
-impl<I: Interner> DebugWithInfcx<I> for ExistentialPredicate<I> {
-    fn fmt<Infcx: rustc_type_ir::InferCtxtLike<Interner = I>>(
-        this: rustc_type_ir::WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        fmt::Debug::fmt(&this.data, f)
-    }
-}
-
 impl<I: Interner> ty::Binder<I, ExistentialPredicate<I>> {
     /// Given an existential predicate like `?Self: PartialEq<u32>` (e.g., derived from `dyn PartialEq<u32>`),
     /// and a concrete type `self_ty`, returns a full predicate where the existentially quantified variable `?Self`
@@ -459,7 +449,8 @@ impl AliasTermKind {
     Copy(bound = ""),
     Hash(bound = ""),
     PartialEq(bound = ""),
-    Eq(bound = "")
+    Eq(bound = ""),
+    Debug(bound = "")
 )]
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic, Lift_Generic)]
 #[cfg_attr(feature = "nightly", derive(TyDecodable, TyEncodable, HashStable_NoContext))]
@@ -493,23 +484,6 @@ pub struct AliasTerm<I: Interner> {
     _use_alias_term_new_instead: (),
 }
 
-impl<I: Interner> std::fmt::Debug for AliasTerm<I> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<I: Interner> DebugWithInfcx<I> for AliasTerm<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut std::fmt::Formatter<'_>,
-    ) -> std::fmt::Result {
-        f.debug_struct("AliasTerm")
-            .field("args", &this.map(|data| data.args))
-            .field("def_id", &this.data.def_id)
-            .finish()
-    }
-}
-
 impl<I: Interner> AliasTerm<I> {
     pub fn new(
         interner: I,
diff --git a/compiler/rustc_type_ir/src/region_kind.rs b/compiler/rustc_type_ir/src/region_kind.rs
index 48ade273289..37c9532ad89 100644
--- a/compiler/rustc_type_ir/src/region_kind.rs
+++ b/compiler/rustc_type_ir/src/region_kind.rs
@@ -4,7 +4,7 @@ use rustc_data_structures::stable_hasher::{HashStable, StableHasher};
 use rustc_macros::{HashStable_NoContext, TyDecodable, TyEncodable};
 use std::fmt;
 
-use crate::{DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
+use crate::{DebruijnIndex, Interner};
 
 use self::RegionKind::*;
 
@@ -18,18 +18,6 @@ rustc_index::newtype_index! {
     pub struct RegionVid {}
 }
 
-impl<I: Interner> DebugWithInfcx<I> for RegionVid {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match this.infcx.universe_of_lt(*this.data) {
-            Some(universe) => write!(f, "'?{}_{}", this.data.index(), universe.index()),
-            None => write!(f, "{:?}", this.data),
-        }
-    }
-}
-
 /// Representation of regions. Note that the NLL checker uses a distinct
 /// representation of regions. For this reason, it internally replaces all the
 /// regions with inference variables -- the index of the variable is then used
@@ -230,12 +218,9 @@ impl<I: Interner> PartialEq for RegionKind<I> {
     }
 }
 
-impl<I: Interner> DebugWithInfcx<I> for RegionKind<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut core::fmt::Formatter<'_>,
-    ) -> core::fmt::Result {
-        match this.data {
+impl<I: Interner> fmt::Debug for RegionKind<I> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
             ReEarlyParam(data) => write!(f, "{data:?}"),
 
             ReBound(binder_id, bound_region) => {
@@ -247,7 +232,7 @@ impl<I: Interner> DebugWithInfcx<I> for RegionKind<I> {
 
             ReStatic => f.write_str("'static"),
 
-            ReVar(vid) => write!(f, "{:?}", &this.wrap(vid)),
+            ReVar(vid) => write!(f, "{:?}", &vid),
 
             RePlaceholder(placeholder) => write!(f, "{placeholder:?}"),
 
@@ -260,11 +245,6 @@ impl<I: Interner> DebugWithInfcx<I> for RegionKind<I> {
         }
     }
 }
-impl<I: Interner> fmt::Debug for RegionKind<I> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
 
 #[cfg(feature = "nightly")]
 // This is not a derived impl because a derive would require `I: HashStable`
diff --git a/compiler/rustc_type_ir/src/ty_kind.rs b/compiler/rustc_type_ir/src/ty_kind.rs
index 71f3862226d..8b4ad2f5ed0 100644
--- a/compiler/rustc_type_ir/src/ty_kind.rs
+++ b/compiler/rustc_type_ir/src/ty_kind.rs
@@ -10,7 +10,7 @@ use std::fmt;
 pub use self::closure::*;
 use self::TyKind::*;
 use crate::inherent::*;
-use crate::{self as ty, DebruijnIndex, DebugWithInfcx, InferCtxtLike, Interner, WithInfcx};
+use crate::{self as ty, DebruijnIndex, Interner};
 
 use rustc_ast_ir::Mutability;
 
@@ -341,12 +341,10 @@ impl<I: Interner> PartialEq for TyKind<I> {
     }
 }
 
-impl<I: Interner> DebugWithInfcx<I> for TyKind<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        match this.data {
+// This is manually implemented because a derive would require `I: Debug`
+impl<I: Interner> fmt::Debug for TyKind<I> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
             Bool => write!(f, "bool"),
             Char => write!(f, "char"),
             Int(i) => write!(f, "{i:?}"),
@@ -369,27 +367,23 @@ impl<I: Interner> DebugWithInfcx<I> for TyKind<I> {
             }
             Foreign(d) => f.debug_tuple("Foreign").field(d).finish(),
             Str => write!(f, "str"),
-            Array(t, c) => write!(f, "[{:?}; {:?}]", &this.wrap(t), &this.wrap(c)),
-            Pat(t, p) => write!(f, "pattern_type!({:?} is {:?})", &this.wrap(t), &this.wrap(p)),
-            Slice(t) => write!(f, "[{:?}]", &this.wrap(t)),
-            RawPtr(ty, mutbl) => write!(f, "*{} {:?}", mutbl.ptr_str(), this.wrap(ty)),
-            Ref(r, t, m) => write!(f, "&{:?} {}{:?}", this.wrap(r), m.prefix_str(), this.wrap(t)),
-            FnDef(d, s) => f.debug_tuple("FnDef").field(d).field(&this.wrap(s)).finish(),
-            FnPtr(s) => write!(f, "{:?}", &this.wrap(s)),
+            Array(t, c) => write!(f, "[{:?}; {:?}]", &t, &c),
+            Pat(t, p) => write!(f, "pattern_type!({:?} is {:?})", &t, &p),
+            Slice(t) => write!(f, "[{:?}]", &t),
+            RawPtr(ty, mutbl) => write!(f, "*{} {:?}", mutbl.ptr_str(), ty),
+            Ref(r, t, m) => write!(f, "&{:?} {}{:?}", r, m.prefix_str(), t),
+            FnDef(d, s) => f.debug_tuple("FnDef").field(d).field(&s).finish(),
+            FnPtr(s) => write!(f, "{:?}", &s),
             Dynamic(p, r, repr) => match repr {
-                DynKind::Dyn => write!(f, "dyn {:?} + {:?}", &this.wrap(p), &this.wrap(r)),
+                DynKind::Dyn => write!(f, "dyn {:?} + {:?}", &p, &r),
                 DynKind::DynStar => {
-                    write!(f, "dyn* {:?} + {:?}", &this.wrap(p), &this.wrap(r))
+                    write!(f, "dyn* {:?} + {:?}", &p, &r)
                 }
             },
-            Closure(d, s) => f.debug_tuple("Closure").field(d).field(&this.wrap(s)).finish(),
-            CoroutineClosure(d, s) => {
-                f.debug_tuple("CoroutineClosure").field(d).field(&this.wrap(s)).finish()
-            }
-            Coroutine(d, s) => f.debug_tuple("Coroutine").field(d).field(&this.wrap(s)).finish(),
-            CoroutineWitness(d, s) => {
-                f.debug_tuple("CoroutineWitness").field(d).field(&this.wrap(s)).finish()
-            }
+            Closure(d, s) => f.debug_tuple("Closure").field(d).field(&s).finish(),
+            CoroutineClosure(d, s) => f.debug_tuple("CoroutineClosure").field(d).field(&s).finish(),
+            Coroutine(d, s) => f.debug_tuple("Coroutine").field(d).field(&s).finish(),
+            CoroutineWitness(d, s) => f.debug_tuple("CoroutineWitness").field(d).field(&s).finish(),
             Never => write!(f, "!"),
             Tuple(t) => {
                 write!(f, "(")?;
@@ -398,7 +392,7 @@ impl<I: Interner> DebugWithInfcx<I> for TyKind<I> {
                     if count > 0 {
                         write!(f, ", ")?;
                     }
-                    write!(f, "{:?}", &this.wrap(ty))?;
+                    write!(f, "{:?}", &ty)?;
                     count += 1;
                 }
                 // unary tuples need a trailing comma
@@ -407,23 +401,16 @@ impl<I: Interner> DebugWithInfcx<I> for TyKind<I> {
                 }
                 write!(f, ")")
             }
-            Alias(i, a) => f.debug_tuple("Alias").field(i).field(&this.wrap(a)).finish(),
+            Alias(i, a) => f.debug_tuple("Alias").field(i).field(&a).finish(),
             Param(p) => write!(f, "{p:?}"),
             Bound(d, b) => crate::debug_bound_var(f, *d, b),
             Placeholder(p) => write!(f, "{p:?}"),
-            Infer(t) => write!(f, "{:?}", this.wrap(t)),
+            Infer(t) => write!(f, "{:?}", t),
             TyKind::Error(_) => write!(f, "{{type error}}"),
         }
     }
 }
 
-// This is manually implemented because a derive would require `I: Debug`
-impl<I: Interner> fmt::Debug for TyKind<I> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-
 /// Represents the projection of an associated, opaque, or lazy-type-alias type.
 ///
 /// * For a projection, this would be `<Ty as Trait<...>>::N<...>`.
@@ -435,7 +422,8 @@ impl<I: Interner> fmt::Debug for TyKind<I> {
     Copy(bound = ""),
     Hash(bound = ""),
     PartialEq(bound = ""),
-    Eq(bound = "")
+    Eq(bound = ""),
+    Debug(bound = "")
 )]
 #[derive(TypeVisitable_Generic, TypeFoldable_Generic, Lift_Generic)]
 #[cfg_attr(feature = "nightly", derive(TyDecodable, TyEncodable, HashStable_NoContext))]
@@ -555,23 +543,6 @@ impl<I: Interner> AliasTy<I> {
     }
 }
 
-impl<I: Interner> fmt::Debug for AliasTy<I> {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<I: Interner> DebugWithInfcx<I> for AliasTy<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        f.debug_struct("AliasTy")
-            .field("args", &this.map(|data| data.args))
-            .field("def_id", &this.data.def_id)
-            .finish()
-    }
-}
-
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 #[cfg_attr(feature = "nightly", derive(Encodable, Decodable, HashStable_NoContext))]
 pub enum IntTy {
@@ -968,24 +939,6 @@ impl fmt::Debug for InferTy {
     }
 }
 
-impl<I: Interner> DebugWithInfcx<I> for InferTy {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        match this.data {
-            InferTy::TyVar(vid) => {
-                if let Some(universe) = this.infcx.universe_of_ty(*vid) {
-                    write!(f, "?{}_{}t", vid.index(), universe.index())
-                } else {
-                    write!(f, "{:?}", this.data)
-                }
-            }
-            _ => write!(f, "{:?}", this.data),
-        }
-    }
-}
-
 #[derive(derivative::Derivative)]
 #[derivative(
     Clone(bound = ""),
@@ -1078,15 +1031,7 @@ impl<I: Interner> ty::Binder<I, FnSig<I>> {
 
 impl<I: Interner> fmt::Debug for FnSig<I> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        WithInfcx::with_no_infcx(self).fmt(f)
-    }
-}
-impl<I: Interner> DebugWithInfcx<I> for FnSig<I> {
-    fn fmt<Infcx: InferCtxtLike<Interner = I>>(
-        this: WithInfcx<'_, Infcx, &Self>,
-        f: &mut fmt::Formatter<'_>,
-    ) -> fmt::Result {
-        let sig = this.data;
+        let sig = self;
         let FnSig { inputs_and_output: _, c_variadic, safety, abi } = sig;
 
         write!(f, "{}", safety.prefix_str())?;
@@ -1100,7 +1045,7 @@ impl<I: Interner> DebugWithInfcx<I> for FnSig<I> {
             if i > 0 {
                 write!(f, ", ")?;
             }
-            write!(f, "{:?}", &this.wrap(ty))?;
+            write!(f, "{:?}", &ty)?;
         }
         if *c_variadic {
             if inputs.is_empty() {
@@ -1113,7 +1058,7 @@ impl<I: Interner> DebugWithInfcx<I> for FnSig<I> {
 
         match output.kind() {
             Tuple(list) if list.is_empty() => Ok(()),
-            _ => write!(f, " -> {:?}", &this.wrap(sig.output())),
+            _ => write!(f, " -> {:?}", sig.output()),
         }
     }
 }
diff --git a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
index d2a0fb0cb3c..c0f16ee7ec0 100644
--- a/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
+++ b/tests/mir-opt/building/async_await.b-{closure#0}.coroutine_resume.0.mir
@@ -5,12 +5,15 @@
             ty: Coroutine(
                 DefId(0:4 ~ async_await[ccf8]::a::{closure#0}),
                 [
-                (),
-                std::future::ResumeTy,
-                (),
-                (),
-                CoroutineWitness(DefId(0:4 ~ async_await[ccf8]::a::{closure#0}), []),
-                (),
+                    (),
+                    std::future::ResumeTy,
+                    (),
+                    (),
+                    CoroutineWitness(
+                        DefId(0:4 ~ async_await[ccf8]::a::{closure#0}),
+                        [],
+                    ),
+                    (),
                 ],
             ),
             source_info: SourceInfo {
@@ -23,12 +26,15 @@
             ty: Coroutine(
                 DefId(0:4 ~ async_await[ccf8]::a::{closure#0}),
                 [
-                (),
-                std::future::ResumeTy,
-                (),
-                (),
-                CoroutineWitness(DefId(0:4 ~ async_await[ccf8]::a::{closure#0}), []),
-                (),
+                    (),
+                    std::future::ResumeTy,
+                    (),
+                    (),
+                    CoroutineWitness(
+                        DefId(0:4 ~ async_await[ccf8]::a::{closure#0}),
+                        [],
+                    ),
+                    (),
                 ],
             ),
             source_info: SourceInfo {
diff --git a/tests/ui/coherence/occurs-check/associated-type.next.stderr b/tests/ui/coherence/occurs-check/associated-type.next.stderr
index d809a6948f3..f32bb1301da 100644
--- a/tests/ui/coherence/occurs-check/associated-type.next.stderr
+++ b/tests/ui/coherence/occurs-check/associated-type.next.stderr
@@ -1,7 +1,7 @@
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
 error[E0119]: conflicting implementations of trait `Overlap<for<'a> fn(&'a (), ())>` for type `for<'a> fn(&'a (), ())`
   --> $DIR/associated-type.rs:31:1
    |
diff --git a/tests/ui/coherence/occurs-check/associated-type.old.stderr b/tests/ui/coherence/occurs-check/associated-type.old.stderr
index 329086ab7df..d26f7665ee7 100644
--- a/tests/ui/coherence/occurs-check/associated-type.old.stderr
+++ b/tests/ui/coherence/occurs-check/associated-type.old.stderr
@@ -1,11 +1,11 @@
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit) }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, '^0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [*const ?1t, !2_0.Named(DefId(0:27 ~ associated_type[f554]::{impl#3}::'a#1), "'a")], def_id: DefId(0:5 ~ associated_type[f554]::ToUnit::Unit), _use_alias_ty_new_instead: () }
 error[E0119]: conflicting implementations of trait `Overlap<for<'a> fn(&'a (), _)>` for type `for<'a> fn(&'a (), _)`
   --> $DIR/associated-type.rs:31:1
    |
diff --git a/tests/ui/higher-ranked/structually-relate-aliases.stderr b/tests/ui/higher-ranked/structually-relate-aliases.stderr
index 2f1dfd19c48..e1cffa0fc37 100644
--- a/tests/ui/higher-ranked/structually-relate-aliases.stderr
+++ b/tests/ui/higher-ranked/structually-relate-aliases.stderr
@@ -1,5 +1,5 @@
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [?1t, '^0.Named(DefId(0:15 ~ structually_relate_aliases[de75]::{impl#1}::'a), "'a")], def_id: DefId(0:5 ~ structually_relate_aliases[de75]::ToUnit::Unit) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [?1t, !2_0.Named(DefId(0:15 ~ structually_relate_aliases[de75]::{impl#1}::'a), "'a")], def_id: DefId(0:5 ~ structually_relate_aliases[de75]::ToUnit::Unit) }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [?1t, '^0.Named(DefId(0:15 ~ structually_relate_aliases[de75]::{impl#1}::'a), "'a")], def_id: DefId(0:5 ~ structually_relate_aliases[de75]::ToUnit::Unit), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: [?1t, !2_0.Named(DefId(0:15 ~ structually_relate_aliases[de75]::{impl#1}::'a), "'a")], def_id: DefId(0:5 ~ structually_relate_aliases[de75]::ToUnit::Unit), _use_alias_ty_new_instead: () }
 error[E0277]: the trait bound `for<'a> T: ToUnit<'a>` is not satisfied
   --> $DIR/structually-relate-aliases.rs:13:36
    |
diff --git a/tests/ui/traits/next-solver/issue-118950-root-region.stderr b/tests/ui/traits/next-solver/issue-118950-root-region.stderr
index 17da1f52479..04c44276195 100644
--- a/tests/ui/traits/next-solver/issue-118950-root-region.stderr
+++ b/tests/ui/traits/next-solver/issue-118950-root-region.stderr
@@ -25,10 +25,10 @@ help: this trait has no implementations, consider adding one
 LL | trait ToUnit<'a> {
    | ^^^^^^^^^^^^^^^^
 
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc) }
- WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc) }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc), _use_alias_ty_new_instead: () }
+ WARN rustc_infer::infer::relate::generalize may incompletely handle alias type: AliasTy { args: ['^0.Named(DefId(0:15 ~ issue_118950_root_region[d54f]::{impl#1}::'a), "'a"), ?1t], def_id: DefId(0:8 ~ issue_118950_root_region[d54f]::Assoc), _use_alias_ty_new_instead: () }
 error[E0119]: conflicting implementations of trait `Overlap<fn(_)>` for type `fn(_)`
   --> $DIR/issue-118950-root-region.rs:19:1
    |