From b7d873e070d9fbbcc99e07800acf66ebcd7c2bac Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 6 Oct 2023 19:40:16 +0000
Subject: [PATCH] Bump COINDUCTIVE_OVERLAP_IN_COHERENCE

---
 compiler/rustc_lint_defs/src/builtin.rs       |  4 ++--
 ...rn-when-cycle-is-error-in-coherence.stderr | 20 +++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 69b462d32bd55..d5e45987ae2b6 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -4489,11 +4489,11 @@ declare_lint! {
     /// on itself), the blanket impl is not considered to hold for `u8`. This will
     /// change in a future release.
     pub COINDUCTIVE_OVERLAP_IN_COHERENCE,
-    Warn,
+    Deny,
     "impls that are not considered to overlap may be considered to \
     overlap in the future",
     @future_incompatible = FutureIncompatibleInfo {
-        reason: FutureIncompatibilityReason::FutureReleaseErrorDontReportInDeps,
+        reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
         reference: "issue #114040 <https://github.com/rust-lang/rust/issues/114040>",
     };
 }
diff --git a/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr
index 89289767b838b..5b0ead1bea0f4 100644
--- a/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr
+++ b/tests/ui/coherence/warn-when-cycle-is-error-in-coherence.stderr
@@ -19,3 +19,23 @@ LL | #![deny(coinductive_overlap_in_coherence)]
 
 error: aborting due to previous error
 
+Future incompatibility report: Future breakage diagnostic:
+error: implementations of `PartialEq<Interval<_>>` for `Interval<_>` will conflict in the future
+  --> $DIR/warn-when-cycle-is-error-in-coherence.rs:13:1
+   |
+LL | #[derive(PartialEq, Default)]
+   |          --------- the second impl is here
+...
+LL | impl<T, Q> PartialEq<Q> for Interval<T>
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the first impl is here
+   |
+   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
+   = note: for more information, see issue #114040 <https://github.com/rust-lang/rust/issues/114040>
+   = note: impls that are not considered to overlap may be considered to overlap in the future
+   = note: `Interval<_>: PartialOrd` may be considered to hold in future releases, causing the impls to overlap
+note: the lint level is defined here
+  --> $DIR/warn-when-cycle-is-error-in-coherence.rs:1:9
+   |
+LL | #![deny(coinductive_overlap_in_coherence)]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+