From 3a9dacd052016254b0a693e7943c0eff525f0559 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Mon, 14 May 2018 00:06:39 +0900
Subject: [PATCH] Do not use bare raise statement

---
 sphinx/builders/epub3.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sphinx/builders/epub3.py b/sphinx/builders/epub3.py
index 008942a6a..8c32231bd 100644
--- a/sphinx/builders/epub3.py
+++ b/sphinx/builders/epub3.py
@@ -185,7 +185,7 @@ class Epub3Builder(_epub_base.EpubBuilder):
                 navstack[-1].children.append(navpoint)
                 navstack.append(navpoint)
             else:
-                raise
+                raise RuntimeError('Should never reach here. It might be a bug.')
 
         return navstack[0].children