From e61dbefc7f250edc955f3b15813e548ebf7a4d72 Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 1 Sep 2012 23:12:18 +0530
Subject: [PATCH] ...

---
 src/calibre/devices/interface.py | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/calibre/devices/interface.py b/src/calibre/devices/interface.py
index 4777cafbe9..d0b2611ead 100644
--- a/src/calibre/devices/interface.py
+++ b/src/calibre/devices/interface.py
@@ -543,6 +543,10 @@ class DevicePlugin(Plugin):
         '''
         Given a list of paths, returns another list of paths. These paths
         point to addable versions of the books.
+
+        If there is an error preparing a book, then instead of a path, the
+        position in the returned list for that book should be a three tuple:
+            (original_path, the exception instance, traceback)
         '''
         return paths