From c47df30a0bf069edb9a280031fa09f0714b5d5f3 Mon Sep 17 00:00:00 2001
From: Wesley Wiser <wwiser@gmail.com>
Date: Mon, 5 Jun 2017 21:52:34 -0400
Subject: [PATCH] syntax_pos::Symbol should not implement Sync

Fixes #42407
---
 src/libsyntax_pos/symbol.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libsyntax_pos/symbol.rs b/src/libsyntax_pos/symbol.rs
index 73c0256f2c1f5..6b5caff27e8f0 100644
--- a/src/libsyntax_pos/symbol.rs
+++ b/src/libsyntax_pos/symbol.rs
@@ -81,6 +81,7 @@ pub struct Symbol(u32);
 
 // The interner in thread-local, so `Symbol` shouldn't move between threads.
 impl !Send for Symbol { }
+impl !Sync for Symbol { }
 
 impl Symbol {
     /// Maps a string to its interned representation.