From 690d5aa417f5d8f8d6157e5a897df5d7dd2ef59a Mon Sep 17 00:00:00 2001
From: lcnr <rust@lcnr.de>
Date: Mon, 6 May 2024 21:33:57 +0000
Subject: generalize hr alias: avoid unconstrainable infer vars

---
 compiler/rustc_trait_selection/src/solve/inspect/build.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

(limited to 'compiler/rustc_trait_selection/src')

diff --git a/compiler/rustc_trait_selection/src/solve/inspect/build.rs b/compiler/rustc_trait_selection/src/solve/inspect/build.rs
index 466d0d80060..a6aebc8d65a 100644
--- a/compiler/rustc_trait_selection/src/solve/inspect/build.rs
+++ b/compiler/rustc_trait_selection/src/solve/inspect/build.rs
@@ -372,7 +372,10 @@ impl<'tcx> ProofTreeBuilder<'tcx> {
                 (
                     DebugSolver::GoalEvaluation(goal_evaluation),
                     DebugSolver::CanonicalGoalEvaluation(canonical_goal_evaluation),
-                ) => goal_evaluation.evaluation = Some(canonical_goal_evaluation),
+                ) => {
+                    let prev = goal_evaluation.evaluation.replace(canonical_goal_evaluation);
+                    assert_eq!(prev, None);
+                }
                 _ => unreachable!(),
             }
         }
-- 
cgit 1.4.1-3-g733a5