From 8179a4be8aa2aeff32d1e8aca1bb58aee4271533 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Thu, 22 Mar 2018 12:22:03 -0400
Subject: [PATCH] use infcx.tcx, so we get the local tcx

The use of tcx/gcx in this function is subtle.
---
 src/librustc_typeck/coherence/builtin.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/librustc_typeck/coherence/builtin.rs b/src/librustc_typeck/coherence/builtin.rs
index 8a1f827749a7..bc674aa15fdc 100644
--- a/src/librustc_typeck/coherence/builtin.rs
+++ b/src/librustc_typeck/coherence/builtin.rs
@@ -372,7 +372,7 @@ pub fn coerce_unsized_info<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
             }
         };
 
-        let mut fulfill_cx = TraitEngine::new(tcx);
+        let mut fulfill_cx = TraitEngine::new(infcx.tcx);
 
         // Register an obligation for `A: Trait<B>`.
         let cause = traits::ObligationCause::misc(span, impl_node_id);