From 6df1b2df261efb2c1c2f09ff3617210f77b92492 Mon Sep 17 00:00:00 2001
From: lcnr <rust@lcnr.de>
Date: Mon, 9 Mar 2026 07:19:18 +0100
Subject: [PATCH 1/2] `FindParamInClause` non-global on overflow

---
 .../src/solve/assembly/mod.rs                 | 42 +++++++++++--------
 .../normalize-param-env-4.next.stderr         | 20 ++++++++-
 2 files changed, 43 insertions(+), 19 deletions(-)

diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index 038168ca638b4..15da2cba6bd59 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -1273,16 +1273,19 @@ where
             return ControlFlow::Break(Err(NoSolution));
         };
 
-        if let ty::Placeholder(p) = ty.kind() {
-            if p.universe() == ty::UniverseIndex::ROOT {
-                ControlFlow::Break(Ok(()))
-            } else {
-                ControlFlow::Continue(())
+        match ty.kind() {
+            ty::Placeholder(p) => {
+                if p.universe() == ty::UniverseIndex::ROOT {
+                    ControlFlow::Break(Ok(()))
+                } else {
+                    ControlFlow::Continue(())
+                }
             }
-        } else if ty.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_RE_INFER) {
-            ty.super_visit_with(self)
-        } else {
-            ControlFlow::Continue(())
+            ty::Infer(_) => ControlFlow::Break(Ok(())),
+            _ if ty.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER) => {
+                ty.super_visit_with(self)
+            }
+            _ => ControlFlow::Continue(()),
         }
     }
 
@@ -1292,16 +1295,19 @@ where
             return ControlFlow::Break(Err(NoSolution));
         };
 
-        if let ty::ConstKind::Placeholder(p) = ct.kind() {
-            if p.universe() == ty::UniverseIndex::ROOT {
-                ControlFlow::Break(Ok(()))
-            } else {
-                ControlFlow::Continue(())
+        match ct.kind() {
+            ty::ConstKind::Placeholder(p) => {
+                if p.universe() == ty::UniverseIndex::ROOT {
+                    ControlFlow::Break(Ok(()))
+                } else {
+                    ControlFlow::Continue(())
+                }
             }
-        } else if ct.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_RE_INFER) {
-            ct.super_visit_with(self)
-        } else {
-            ControlFlow::Continue(())
+            ty::ConstKind::Infer(_) => ControlFlow::Break(Ok(())),
+            _ if ct.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER) => {
+                ct.super_visit_with(self)
+            }
+            _ => ControlFlow::Continue(()),
         }
     }
 
diff --git a/tests/ui/traits/next-solver/normalize/normalize-param-env-4.next.stderr b/tests/ui/traits/next-solver/normalize/normalize-param-env-4.next.stderr
index f5fd9ce9864ce..e91a48f62aec3 100644
--- a/tests/ui/traits/next-solver/normalize/normalize-param-env-4.next.stderr
+++ b/tests/ui/traits/next-solver/normalize/normalize-param-env-4.next.stderr
@@ -4,6 +4,24 @@ error[E0275]: overflow evaluating the requirement `<T as Trait>::Assoc: Trait`
 LL |     <T as Trait>::Assoc: Trait,
    |                          ^^^^^
 
-error: aborting due to 1 previous error
+error[E0275]: overflow evaluating the requirement `<T as Trait>::Assoc well-formed`
+  --> $DIR/normalize-param-env-4.rs:19:26
+   |
+LL |     <T as Trait>::Assoc: Trait,
+   |                          ^^^^^
+
+error[E0275]: overflow evaluating the requirement `T: Trait`
+  --> $DIR/normalize-param-env-4.rs:32:19
+   |
+LL |     impls_trait::<T>();
+   |                   ^
+   |
+note: required by a bound in `impls_trait`
+  --> $DIR/normalize-param-env-4.rs:15:19
+   |
+LL | fn impls_trait<T: Trait>() {}
+   |                   ^^^^^ required by this bound in `impls_trait`
+
+error: aborting due to 3 previous errors
 
 For more information about this error, try `rustc --explain E0275`.

From 3564a3f25956c3483c5c8787a559055255f39cca Mon Sep 17 00:00:00 2001
From: lcnr <rust@lcnr.de>
Date: Mon, 9 Mar 2026 07:59:29 +0100
Subject: [PATCH 2/2] recur into aliases TODO test

---
 .../rustc_next_trait_solver/src/solve/assembly/mod.rs  | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
index 15da2cba6bd59..10721bdaa636c 100644
--- a/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
+++ b/compiler/rustc_next_trait_solver/src/solve/assembly/mod.rs
@@ -1282,7 +1282,10 @@ where
                 }
             }
             ty::Infer(_) => ControlFlow::Break(Ok(())),
-            _ if ty.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER) => {
+            _ if ty.has_type_flags(
+                TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER | TypeFlags::HAS_ALIAS,
+            ) =>
+            {
                 ty.super_visit_with(self)
             }
             _ => ControlFlow::Continue(()),
@@ -1304,7 +1307,10 @@ where
                 }
             }
             ty::ConstKind::Infer(_) => ControlFlow::Break(Ok(())),
-            _ if ct.has_type_flags(TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER) => {
+            _ if ct.has_type_flags(
+                TypeFlags::HAS_PLACEHOLDER | TypeFlags::HAS_INFER | TypeFlags::HAS_ALIAS,
+            ) =>
+            {
                 ct.super_visit_with(self)
             }
             _ => ControlFlow::Continue(()),