From a45d482a976a69aecd46dda0d29251dc73cb96d2 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Tue, 9 Oct 2018 18:00:27 -0400
Subject: [PATCH] more descriptive assertion failure for overflow

---
 src/runtime.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/runtime.rs b/src/runtime.rs
index a6c2a52d..e032453d 100644
--- a/src/runtime.rs
+++ b/src/runtime.rs
@@ -80,7 +80,7 @@ where
         }
 
         let old_revision = self.shared_state.revision.fetch_add(1, Ordering::SeqCst);
-        assert!(old_revision != usize::max_value());
+        assert!(old_revision != usize::max_value(), "revision overflow");
         let result = Revision {
             generation: 1 + old_revision as u64,
         };